My husband and I have been diving with VT3 computers for over 3 years and have found them to be extremely solid and reliable. When we first got them, it appears there was a "bad batch" that put them into altitude mode, but Oceanic immediately replaced them with brand new units, no questions, no hassle. The replacements ones are just over 2 years old and going strong, no hiccups, no problems.
We started with them on retractors with the compass mounts, but within a year had moved them to the wrist and much happier with that configuration. We also very rarely lose the signal, but it is always reaquired within seconds, so no big deal.