Fine machine for limited demand uses and if you like acidy light roasts and pungent dark roasts.
Positive Product Points
The white-based (newer model) Precision is easy to use, easy to clean, and for me, completely reliable. It's roasts are relatively immune to ambient air temp differences--I've used it down to about 46 degrees F on the same setting as I would use at 75 degrees F. Roasts very evenly and through the full range of roasts. Good chaff collector, too.
Negative Product Points
The small roast capacity (3 oz) became for me, something of a chore when I found myself roasting every day or every other day to meet the coffee and expresso needs of a two-person, coffee drinking household. As noted by others, the Precision is also noisy, making detection of the second crack particulary difficult. I found it works best if you dismantle the base and lubricate the bearing with machine oil about every 10-12 roasts (three screws--not a difficult job). Still loud but better, and I believe it extends the life of the machine.
After having run about 50 lbs through the Precision (what's that, 250+ roasts?) the machine still is running flawlessly (note oiling comment above). But I was tiring of daily or near daily roasting to meet the needs of a two person household and have now acquired a new Alpenrost (8 oz drum roaster) and relegated the Precision to a back-up role. If you buy roasted coffee and only want to supplement that with occasional home roasting, or for roasting special beans or blends, or if you are a single- person coffee household, the Precision would be ideal.
The Precision, being an air popper, roasts fast. However, dark roasts tend to be pungent while light roasts tend toward sharper acidity. That's fine if you like coffee that way (I don't) but not the best if you don't, or if you drink espresso or prefer deeper body and more complexity in a brewed coffee. If you do, a drum roaster or stove-top roaster might be a better idea than the Precision, Fresh Roast or any other air-popper. (I think that some of the complaints about home roasted coffee being "bitter" or "sharp" are from people who are not used to air-popped coffee and perhaps, don't like it's sharper or more pungent nature).
Because of the noise, judging roast doneness is best accomplished by sight or smell with the Precision. The clear glass base and slow rolling bean movement make this easy to do. All parts that get gummed up are easy to clean and can be put in the dishwasher occasionally. In this regard, (visible roast clues, clean-up, chaff collector) the Precision is superior to the Alpenrost. In other regards such as quantity roasted, full bodied more mellow and complex taste (for me at least), the Alpenrost is superior.
I think that the bad press on Hearthware reliability is not warranted in regard to the white-based Precision-- particularly if you perform some bearing maintenance regularly as noted (not in the manual).
Originally bought from Sweet Marias with their usual fine service.
Three Month Followup
The Precision remains my back-up machine and the one I use occasionally to satisfy a whim for snappy, acidy coffee. I also find it useful to add a lighter roast, highlight coffee to a softer, darker espresso base roasted in the Alpenrost. The Precision is still completely reliable and is less fussy than the Alp in most respects.
I have noticed that beans in lighter roasts are not uniformly roasted. If you break apart a single bean you can often find the center to have a lighter color than the outside. Never happens in the Alp and I attribute it to the fast roast times in the Precision--and probably all other fast, fluid bed machines such as the even faster Fresh Roast as well.
It appears that the Precision may have gone out of production. Sweet Marias now lists it as unavailable and has replaced it with the older HW Gourmet. Pity--if you can find one, the white-based Precision is undoubtedly a better machine.