I've said before that there's nothing in the world wrong with the spyder, and doubly so at the price. I feel very strongly that it's by FAR the best light you can buy for $13.50 (w/ batteries and nylon sheath), and that the price forgives the lousy beam and switch.
Relative to an $80 e2e, the price/performance ratio is hard to support - it's not a 2.5x price advantage as stated above (correct for the pair of Spyders), but more like a 6x price differential. e2e is superior in nearly every particular of construction, handling, long-term reliability, etc., but it's hard to argue you'd be better off with one e2e than six Spyders.
That said, the e2e is also my least favorite surefire - I think you get a much better deal on the G2, and I'd argue you're better off with one G2 than two Spyders.
All that said, I mostly use my Spyders as 'loaner' lights - people who come to me and ask to borrow one of my 'super-bright' lights - they get Spyders, and I'm never sad if they don't come back.
I'd also never take a Spyder anywhere it might be my only light. They're great to own in the drawer, but if I'm going to depend on one light, it'll be an Arc, Surefire, Inova or perhaps a FireFly. It will be a cold day in hell before I trust a Spyder to work when I really need it.