Since all you RC-people seem to like these Dremel tools so much I'm thinking about getting one.
What I don't get is what you use these Dremels for that makes them almost "mandatory"?
I mean, some people here on the forum say they own five of 'em ???

I use a cordless powerdrill for drilling holes, a #11 hobby knife for cutting, sandpapers for sanding and a small handsaw for sawing balsa and plywood.
OK, I might be a rookie, but I have successfully assembled/built:
-GP PT40 ARF
-2 x Durastick's
-2x Scratchbuilt F4U foamie combat planes (.21 size)
-WM Skyraider Mach2
-Modelfly Beaver
-Raptor 50 heli

...And to be honest, my tools have been sufficient and I don't understand why everybody is so fired up about the Dremels?
Please enlighten me and give me a good reason to buy a new toy!

I have two Dremels and I use them to cut piano wire, grind some piece of wood and do many things with them.

In fact, beside cutting piano wire, I think you can go without one but once you get one, you'll wonder how you could go without it.

Well I'm not too happy with the cordless dremel I got last year. Just the other night, the high speed crapped out. Only the low speed works. I checked the battery contacts and it looks fine,but still no high speed. Anyone know how long the warranty is on these things?

A Dremel tool is not an absolute necessity. Kits were built long before Dremel was around. They do make some things easier and they save time. If you are happy using simple hand tools and get good results then by all means stick with them. The planes you have listed probably wouldn't see much use from a Dremel anyway (helis, ARF's and foamies). I have one I have had for 15-20 years and I use it all the time and not just on planes. They aren't the solution to everything...I still use the good old razor plane, sandpaper and files when building.

the cutting disk is the best tool i can think of for cutting fiberglass cowls.

I'd really like to get one, but I need to justify it somehow.
For a scratchbuilder I understand it's great and very important to cut, sand and shape all those parts, but for normal kit building and ARF assembly I don't know.
Cutting wire with that spinning disc is not a good reason enough, I have a good set of pliers and a big biceps that'll do the cutting all day long (J/K)
Perhaps I should go down to the hardware store and check them out, if I know myself right, I'll instantly find many reasons to get one and I'll won't drive home empty handed

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