I have been looking at coffee roasters for well over a year, but have been disappointed by the current options.  Basically, most of the current crop of home-use roasters (with possibly the exception of the Behmor) seem somewhat flaky and poorly constructed.  I looked at more than a few of them, and they just didn't seem likely to last out the year.  It seemed to be stretching things to pay the amount of money that many cost if I wouldn't get that much use out of them.  Also, all of the posts about voltage problems in houses with these roasters had me pretty alarmed.  I read posts about people needing variacs and line voltage problems with the roasters, and that combined with the construction problems I had seen were just too much of a red flag.  So I put off getting any of the roasters.

But then I noticed www.rkdrums.com and it seemed like a very good solution.  The drums looked well built and unlikely to fall apart in a year.  Also, since it used a propane grill, no worries about voltage issues.  My only concern with rkdrums was assembling the thing.  This was solved very easily though when Shane Lewis (see buying experience below for more details) agreed to assemble one for me.

I have done 6 roasts with the unit so far, and that seems to be enough at least to get a review started I think.  Using the unit is very easy:

(1) Preheat grill to 500+ degrees F with drum outside of grill
(2) Insert beans in drum and close drum.
(3) Insert drum in grill.
(4) Flip switch to get drum rotating and start timer.
(5) Control temperature profile during roast.  There are many recipes at www.rkdrums.com with sample
profiles.  I found it not very hard and all of my roasts have turned out pretty well (if I say so myself...)
(6) Take drum out of grill.  With one hand you can hold the rotisserie handle but you will want a nice glove for the other hand.  The rkdrums site recommends ove glove.  I bought a pair of foundry gloves from
amazon.com (for under $30) that can withstand prolonged (i.e., more than temporary) exposure to 600 deg F temps so that I could sit there all day holding the spit if I wanted to.
(7) Remove pin from drum door.  This is really the only design flaw I see.  I think maybe some other sort of latch would have worked better.  I see why they opted for the pin, though.  It is simple and you don't worry about the heat ruining a spring or anything like that.  It's not like it is very complicated either (rather easy, actually).  It's just that this step could be smoother if you just had to flip a latch or something.
(8) Put beans in a kitchen sieve over a fan.  I notice some people had assembled box fans on a wooden frame.  Because I am lazy, I bought a 20" circular fan with stand (a workshop-ish one) that can be pointed straight up and just put the 20" sieve right on top of it.
(9) Stir beans (not long, they cool down in just a minute or so.)
(10) Clean everything up, put away grill, etc.

All in all, it is very direct.  You don't have to fiddle with some electronic program to get it to do what you want it to do.  Just set the temp as you like it.  It seems much more direct and pleasant.  I did a range of roasts, from city-ish to full city to vienna, and am satisfied with all of them.  It is very easy to hear the beans cracking, even though I had previously only read FAQs about what to expect.

The unit is constructed extremely well.  In fact, it is painfully obvious that the only shoddy construction is that coming from the grill itself or the rotisserie spit.  The drum looks build like a tank.  The motor assembly is mounted to an extremely thick metal plate and looks very solid.  It all looks like commercial quality contruction.

The $490.00 price is for the 4 lb combo and drum and motor and mounts.  I actually paid more than this because I asked Shane Lewis (the new person running www.rkdrums.com) to assemble/buy an entire unit (grill + drum + motor + sheet metal work) for me.  He did this very quickly and cheerfully (and with minumum charge) and shipped everything to me.  There was some damage to the grill in shipping, but he sent a check for $12 to cover the replacement parts from the grill manufacturer.  I am very satisfied with all of my dealing with him and the buying experience was very pleasant.