My 50's Pfaff has a nice small free arm, but it's belt driven. The belts are thick and cleated and as far as I can tell will last just about forever - not a rubber belt you'd need to replace anytime soon.
As an alternative, I think the slant-shank Singers are really good for sewing cuffs and the like, despite their flat bed. That slant setup puts the needle in a good spot where you can really see what you're doing, and it's not too hard to sew cuffs and collars from the inside like Macybaby said. I don't sew a lot of clothes but I recently sewed up a couple of cup sleeves for my DH and I used my 500A with good results - the cup sleeves were too small to fit over any free arm I own! I've also used my big honkin' Janome to make those in the past, again sewing from the inside. It was definitely easier on the slant shank.
(Cup sleeves...is that the right name for those things? The little heat protectors for hot to-go cups is what I'm talking about- DH says the cardboard ones they give out at SBux are wasteful so I make them for him from scraps.
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