I did'nt read the whole thread, so this may have been covered already.
Follow this link,
MANTAINDUSTRIES.COMgo to products, and look at the small SPG. I ordered one last week. I think it fits the minimalist idea. For me, I would rather have a backup so I don't necessarily have to end the dive just because of computer problems. The expense is worth the fact that I may never need it. So what. I'm a serious diver. I payed bux to do this dive, I payed extra bux to make sure I have MAX BT.
Mr. B
.02psi