Friend has an Enduro and it seems to go up hill very well when I've tried it. Always seem to be good deals around on them, so lots of bang for your buck. He has however had big issues with the fork, lossing pressure etc. That said it was replaced under warrenty no problem and has been great since.
Tride a 575 on a Demo day. Really liked it, can be built up lots of ways and seem to last well.
Had a couple of goes on a 5, not for me. Seems to bob a lot on the climbs, good on the downs, but so are all the others.
Not rode an E5, but rode an E120. Not convinced, pedalled wellish, but I found it a bit like the 5, bobby. Nothing like as good as the others on the downs.
Have you also considered the likes of the Ellsworth Epiphaney. I would sayway better that all the others on the ups and still as good on the downs. (and I dont even own one anymore).