Bests & Worsts Reviews from Amazon

I was contemplating buying the 7700 (7.2V), 8000 (10.8V) or 8200 (12V). My main reason for buying was to "dremel" my dog's nails but I also wanted the flexibility to use on various household projects. My biggest concern with cordless devices is the battery, stay away from NiCad or NiMH if you can. I've had other brands of rotary tools with those old batteries and while the tool works fine for the first couple of months, the battery quickly degrades - device loses torque without ramping up the RPM which can cause lots of heat transfer. The new Lithium battery holds a charge much longer even if the device is not being used, can top off anytime as well - notice how all new cellphones are switching to Lithium? The new 8220 has the newest Lithium battery so I'm hoping it will last longer than the 8200 which has mixed reviews on the battery. For me, the price difference between the 7700, 8000 vs 8200 was justifiable because a replacement battery quickly makes up the price difference. I dremel once a week or two - even at that rate the old NiCad and NiMH were not holding charge very well. The 8220 definitely is plasticky. This should be fine for home hobby use but definitely not professional grade - that is don't expect it to last long if you drop it on concrete. I'm happy with the build quality and the use of plastic because for the work I'm doing I don't want a device that's too heavy and unwieldy. The plastic box doesn't leave room to store any other accessories. The included accessories are a small sample of what Dremel makes - incidentally while there are lots of 3rd party manufacturers of Dremel accessories, I've found Dremel branded material to be higher quality. The 8220 is fairly quiet even when notched up to 30,000 RPM. I'm mainly using 5,000-10,000 RPM on my dog and it's much quieter than other rotary tools I've had in the past. Update 2013/03: I'm still very glad I purchased this model. The battery is amazing and has no problem holding charge despite weekly use. Would not hesitate to get another one.