Hello!
I have built models for many years without a Dremel but started using one 15 years ago.
For routing, cutting and sanding special objects the Dremel is very nice to have.
I especially like the wolfram carbide cutters from Micro Mark which are so good to have when you want to take up holes in plywood and fiberglass. The sanding drum is also very nice to have when sanding formers and taking up holes....making it easy to make my models lighter.
For cutting piano wire I use the glass reinforced disk from Dremel.

Regards!
Jan K
Sweden