Knowing how the Dremel is revered by some people dare I say I've always thought them to be a bit overrated, over priced and actually quite limited with what they can do I had a Dremel a few years ago and quickly realised it's limitations and that of it's accessories, cutting discs don't last long and break easily, grinding stones wear away quickly and IIRC 5mm is about the biggest drill you can use and what use is 20,000 rpm if it has so little torque it stops spinning when you lean on it too much, I guess a Dremel could be used for light work like jewelery or something but I've always thought that for most PC modding work especially metalwork they don't have enough torque. For what a Dremel costs you can buy a cheap normal size drill and a few bigger cutting discs and grinding stones that will take much more abuse and last longer also with a decent size chuck you can use bigger drills and with drill stand you've got a simple pillar drill, get a decent flexible drive and it can get to most areas a Dremel can without having to worry about using too much force and stopping the drill, I didn't find too many uses for my Dremel and sold it, I think of Dremels as being like exercise bikes, you use them for a while and then they gather dust
They're not really about torque - they're never going to compete with a proper drill - that's why they spin up to 30,000 rpm Noisy, messy but very useful for dealing with smaller sections of alu and steel rather than going through the hassle of benchtable, pilot hole, jigsaw etc... I find the drill bit is perfect for dealing with rivets too - a normal drill actually has too much torque sometimes and the half-dead rivet just snaps and ends up rotating in the hole. The Dremel is much easier to dig it out with. The cutting discs will last if you use them with the right materials (non-dremel fittings are usually inferior and last even less time too) - anything metal you'd be well advised to use the reinforced cutting discs. I mainly use mine for acrylic work and it's brilliant here as all their fittings come into play with the softer material.
Yeah, Dremels in many ways are something of a throw back to old school modding. Cutting out small sections of thin steel or aluminium, cutting fan mounts to size, shaping a bit of mesh, grinding off the mounts for a drive bay, etc. The sort of thing you could get away with doing indoors rather than in the garage/shed. With the scale of many modern projects - particularly scratch builds - they have indeed lost much of their usefulness. However, they're still great tools to have around - especially battery powered ones - simply because of their versatility.