I think you might find the Proxxon Micromot tools are also much quieter than the Dremel, have less runout (are more precise), don't need the bushings changed due to wear, are designed to run continuously and are available in either AC or DC versions.
Someone else on the forum kindly guided me towards these Proxxon grinders, after looking into them and confirming their advantages it was hard not to be impressed - plus they are more common than many of the low cost dedicated cnc options, though significantly more expensive than a Dremel.
It seems the Dremel is quite accurately made until the final shaft/collet design and manufacture, a collet being much more accurate than a chuck, its this shaft/collet part of the Dremel that causes the 'wobble' in the cutting bit.
Its interesting that users are dividing into two distinct streams, small low powered precision users and higher power trim router (notably the dewalt trim router) users. Best regards.