Wow, this is super long thread. Couldn't read them all. But, one or two people here talked about how the Cobalt was somehow old-fashioned because it had hard buttons versus only onscreen buttons. The problem with onscreen buttons underwater is the same problem you have with today's touchscreen smart phones while you are wearing gloves (think Minnesota during the winter, or in 2011, think Atlanta during the winter): they don't work. You have to take your gloves off for capacitive screens to work (or have some very custom gloves that include metal in the fingertips).
So, you want a computer that can work in cold water too...dives where you might be wearing gloves. heck, you might even wear gloves during warm water dives. If you did, those touchscreen only computers would not work for you.
TheBaum
Mares Nemo Air