Here is my 2 cents worth: I have been a modeler for over 35 years, both as a hobby and as a profession. While I'm sure there are many good reasons for all sorts of different motor tools, all I have ever needed was my trusty Dremel Multi-Pro. Personally, I would not recommend the cordless variety, simply because I wouldn't want the battery to die in the middle of whatever I'm doing. Sure, you can get spare batteries, but it's just like my cordless drill, with which I do have a spare battery, sooner or later, you are left without power. As for price, I could buy 4 Dremels for $227 US, whatever that translates to, I don't know. Then there are things like the flex-shaft attachment, lights, buzzers, whistles, etc...these are a matter of personal choice. You do need varible speed however, this is a very useful feature to have. Too much speed and your sander will melt your plastic, too little speed, you'll be there all day on the tough stuff like metals. Hope this was somewhat helpful.