Well, i haven't had much of an opportunity to fish them yet, but have tied a few and bent the ear of many a flyshop employee to learn what hooks are being used, what they consider the advantages are of tubes, etc.
I've found that, for large flies, the most popular hook is the Owner Flyliner. Beautiful hook - dark chrome finish, wide gap, Very Sharp, stright eye, and a bit pricey. Definitely top-end. Others are using everything from shortshank saltwater hooks from Tiemco and Mustad to Tiemco globug hooks in the smaller sizes.
The reasons people are fishing them are (1) that they seem to cause less trauma to steelies (and smolt) than the larger irons and (2) that they were getting a better hook-to-hand ratio for winter/spring fish, especially with the really big flies. I've talked to 5 guys that fish tubes exclusively in the winter/spring and all but one said they were convinced they were landing a higher percentage of fish with tube flies. The one exception said it was about the same, but he's a bit eccentric and fishes tube flies mainly because they're "Cool and Different".
Anyway, I've should be getting a shipment of the Owner hooks any day now - if Tyler gets down here on December 22-23 and I've gotten the hooks, I'll send a few back with him so you can check them out.