Böker's been around forever, maintaining Solingen operations for greater than a century.  We've had the brand two years now, & I'd say their workmanship's superior in the average of the fit/finish standards to Dovo or Thiers-Issard.  I personally don't care much about that as long as the razor works, but to each their own; if you want the best workmanship in a blade in terms of pinning, centering, grinding marks, etc etc., and you don't want a 'custom' razor, it is likely true that the Böker brand is the EU's best modern 'production' razor.

Good as Böker's product is, I don't think they should be your choice in a first straight razor.  On paper it may sound like a petty issue, but their preference for a very smooth and slightly rounded razor tang (which is how most of them are made) makes for a razor that requires a bit more familiarity 'round the breed to operate with confidence.  You're better off with any conventionally-file-jimped tang Dovo, or even better are the smaller selection of Dovo 'shoulderless' razors with the thumb depression (current-production Dovo model numbers 26810, 26820, 66810, 76820, 1226850, & 1186810).

Böker's factory edge is pretty decent, but not up to par with Dovo's on its average in this opinion.  We happily hone any model but the 6/8" 'Silver Steel' at no charge...the "Silver Steel", however, is the anomaly in the Böker lineup; not only is it the only model with file jimps on both sides of its meaty tang, but it also comes with a factory edge that I'd term in need of some fairly serious initial lifting in almost every case.  For this, we'll charge for its consumption of too much valued office time relative to its cost; if you're already honing your own razors there's absolutely no need to fear it as a task, it is just time consuming in step #1.

These unassuming-looking sleeves protect razors from rust.  While blessed with no more panache than an '89 Camry, just like that fine tool the damn things just work.  They're definitely a mild eyesore here; I call them my "razor burqas", but nonetheless never remove their presence, which of course also negates the capacity for a spiffy razor or razor-and-brush stand.

Like malaria pills, all you must do is actually use 'em & you'll have nothing to worry about again; they do get less oily over time, but that does not affect their capacity for wicking away moisture.  This is an effective anti-rust solution for a lifetime; it is not merely a barrier prohibiting entry of moisture, but rather a tool which continually draws moisture from the inside to the outside.  Always leave it where it can expunge the moisture to larger environments, and if those larger environs are as crazy humid as a sailboat or a rainforest's interior(~85% at all times), take the extreme step of putting the razors/sleeves in an airtight container with some fresh silica gel packets enclosed within (Ewa Marine's 'CD5' are a very thirsty and reusable desiccant option).

Take a moment to think about just how incredibly colloquial and myopic an online comment such as "I just dry my carbon steel blades, have never had a problem." is; the conditions for oxidation of steel can vary wildly!  A steel's formulation, its level of polish, and the ambient relative humidity of the environment the steel is kept will all have a say in whether steel oxidizes or not.  Succinctly stated, if and when such sage advice as above proves inaccurate for you, it is now your problem.

While it is certainly true that even one of these sleeves will costs nearly a lifetime's supply of a really cheap oil that would be just as effective at preventing rust, if you go the cheapskate route you've got to fuss with oil every damn shave for the rest of your life!  That sounds awesome.  Place yourself anywhere upon the time/$ continuum as you see fit; there is no 'right' answer.

Made for decades by hand in the USA by various American firms for the firearms industry (known as "gun sleeves", "silicone cloths", etc. etc.), these particular oil-and-silicone-treated-cotton sleeves are from 100% USA materials/labor and make oiling steel within irrelevant; I've used them for a high carbon oldie that I never oil, living in a near-constant 70-75% relative humidity environment.  Not a drop of rust anywhere in >3 years.  That's very impressive.  In fact, the makers say to not oil the steel, for this can seal moisture under a film of oil (they've also decreed that if one must be as anal to both sleeve and oil, use a product which allows evaporation-by name they recommended Ballistol).

This is an excellent, practical travel solution, too.

WARNING:  When you get it, the inner surfaces of this little sock sleeve are much more slippery than, say, a dry terry cloth towel.  It is not intended as a protection tomb from impact, and offers no protection from the laws of physics; this is only a tool to eliminate the risk of rust.  If you forget which end of the sleeve is the open end and expose that open end marginally more towards the center of our earth as opposed to away from it, it is very likely that the razor will fall out of it, possibly damaging you, the razor, or both.  Be careful carrying it around.  I myself have already made this stupid mistake once, but still wouldn't trade these things for the world.  One less thing to worry about.

The Böker "Silver Steel", new in 2012, is a 6/8" carbon steel extra full hollow ground 'singing' model, which are the ones I've always preferred; demanding of proper angle of incidence, beard preparation, and great skin stretching, but rewarding when all is dialed in because the 'moment of severing' seems so short with the singers.  Weight's a hefty ~58 grams.  File jimps are present on both sides of the tang, which I greatly appreciate on a singing razor.  

CHOOSE FROM ACTUAL IMAGES OF STOCK BELOW

The Böker "Tree Brand" is a standard-excellence 5/8" full hollow ground model with a handle made of brown canvas Micarta, which is a proprietary fiberglass/paper concoction that's very durable stuff and is used in all sorts of applications ranging from aviation, firearms, and razors.  No file jimps, and an old-fashioned "Tree Brand" logo for the show side of this razor.  There's a bit of variance in the look of Micarta, so we show 'em to you individually.  Figure a weight hovering somewhere around forty-five grams, a medium weight 5/8" with excellent balance and a handle that is pleasant to touch.

CHOOSE FROM ACTUAL IMAGES OF STOCK BELOW

The 4/8" Böker "Extra Hollow Ground" should strike you as a modest razor with a plain little celluloid handle and an unfanciful blade-that's exactly what it is.  But it is a very special blade nonetheless.  It is small (just 32 grams!) and extremely thin ground, much like the Dovo "Prima Klang" and the Thiers-Issard "Evide Sonnant Extra" or "Sheffield Steel" siblings (which functionally are the same, and only differ by polish/handle stock) which I prefer.  I'm not aware of any <5/8" razor beyond this one which is so satisfyingly thinly ground, except for a deceased 4/8" we got once from Solingnen, the Paul Schulze "Extra Feiner Hohlschliff".  It was a better deal buying yesterdecade's leftovers, but they're long gone, or at least the ones which haven't mated to skin yet are.  This is modern time's best emulation of the sorely missed mister Schulze, and in fact the only functional variance that I see/feel (a proud owner of both) is that this one has a 'normal' tang, and not one with file jimps.

I can't tell beginners that these are easy to use-they're probably the worst razor you could pick.  But with experience, give me a little singer to a deserted island with a coticule and scrap of leather and I'll have at least one issue in life solved well.  They're a real maestro's tool.