Rotozips whole separate animal, new Dremel products a response to very
successful marketing by Rorozip.  Rotozip seems much beefier, basic unit
has been around a long time, in use by drywall professionals.  My
Rotozip 'died' within warranty period (after just one use) but instant
response by Rotozip:  Overnight mailed replacement and they paid for
return shipping on bad unit, no questions, no problems, and didn't
demand a receipt to prove it was still in warranty, took my word for it
as to when it was purchased.  Have used it only a little, but pleased,
it seems to work as advertised. My past experience with Dremmel has not
been as good, but that was many years ago, I use very little any more.