Bests & Worsts Reviews from Amazon

At first glance - the 4200 is a very good deal, taken into consideration all the items that are included with the kit compared to individual cost of each included accessories. Unfortunately - in actual real world use - the EZ Change system proves to be the the weakest point of the design. Product Features Most powerful and versatile rotary tool in the Dremel line ( TRUE - but not by much, only 5,000RPM / 30 to 35K difference) EZ Change system-change all Dremel accessories without the wrench or collet lock (not TRUE, in fact, you need 4 sizes of collets (Dremel 4485) / and the worst part, you need a long nose plair to change them which completely defeats the purpose) Cooler running with 20-percent more air flow in venting design (YES- TRUE, but i dont like it, when i set the unit to max power, its like a blower and the air is vented underneath) Variable speed of 5,000 - 35,000 RPM with electronic feedback (TRUE - but not all attachments can be used at 35,000; in real world use, mostly- you will be using 15-25,000RPM) Includes 6 attachments and 40 accessories for maximum versatility (NOT TRUE - this is very misleading - when they say 40, they are actually counting each individual item, like 4 sanding wheels, 6 cutting wheels, 2 brushes, 4 buffers, etc.) - also, the nomenclature included with my 4200 unit was wrong - it listed all the accessories of DREMEL but the 4200 was not listed (what the hell) ~ Also, the DREMEL 4486 Chuck will not work on the EZ change and so far to date - they are not offering any connector/attachment to let you use it. If you plan to buy this - IMHO - you are better off buying the Dremel 4000-6/50 or any 4000 series combos. I end up returning mine and replaced it with the 8220 series. It will cost me more but at least I can use all the Dremel attachments and accessories that I want. Again, the 4200 combo is a great deal for all the attachments included comparable to its price but - if you plan to buy more attachments and different size bits, you will quickly find yourself wanting the 4000 - also the 4000 can be adapted to use the EZ change system but the 4200 is not backward compatible (as of this writing) Hope this helps.