First, I own what I guess is the "old Alp" - rumor has it that Swissmar has recently redesigned the machine to include automatic correction for ambient temperature, which if true, would be a significant improvement. If you're buying now (Early 2002), you may want to ask your retailer how old their inventory is, and whether you're getting the redesigned model.
I don't own any hot-air roasters because their capacities were all too small for me. The best feature of this machine was its capacity. It's very convenient to be able to roast a half pound at a time (you can roast less, but more on that later).
There are many good things about the Alp. I think it's a nice design, reasonably compact, no hot surfaces exposed (even after roasting, so long as you let the cool cycle run its course), and intuitive to use. All parts are accessible for thorough, albeit occassional cleaning. The chaffe collector does a good job collecting chaffe, but if you can, it's handy to have a vacuum nearby to suck up the chaffe between batches. Most importantly, it does a good job roasting the beans - fairly even finish.
Now for the drawbacks. The biggest is the one everybody talks about - variability. The machine is very sensitive to two factors: weight of beans being roasted, and ambient temperature. It's more sensitive to weight than temp (within a reasonable range). You really need a decent scale to ensure consistency. Temp sensitivity is an issue, but it's not counterintuitive. You'll just need several practice pounds, some of which you are bound to ruin. Just prepare yourself for it. There is a learning curve, it is frustrating, but you can master it. Do yourself a favor and keep a roasting notebook for a few months, recoring factors like type of bean roasted, ambient temp, amount roasted, setting, and finish of roasted beans.
There are also other issues. The next biggest one is inability to see the beans while roasting. My ears may be bad, but I think it's difficult to hear the "cracks" over the noise of the motor and the beans tumbling. I've found that it's handy to keep a flashlight nearby and open the lid just enough to "peek".
I have some issues with the bean hopper. First off, it's barely big enough. With a 227 gram (green) load, the hopper fills to capacity and then some, making it hard to remove without spilling a little. Also, there's nothing to prevent you from runnng the machine without the hopper, which I've done on occassion and wound up with half a pound all over the garage floor.
And ahh, the smoke. Forget about using this thing indoors. I've heard tales of venting up the fireplace, using the range hood, out the window, etc. All I can say is I wouldn't do it in my house. I roast in the garage, and still use a plastic dryer house to vent out the window.
Now earlier I said it's possible to roast less than a full load. In theory. If you're running full loads, you will get to the point where you can let the macine go on autopilot. But with anything less than 200 grams, you've gotta watch it like a hawk. Very difficult!!
All things considered, I like the Alp and think it's a good buy at $300.