The Hollis DG03, Aeris Elite T3, and old Oceanic VT3 are all essentially the same computer manufactured by American Underwater Products
American Underwater Products (previously Pelagic Pressure Systems). Oceanic discontinued the VT3 some time ago and now sells the VT4.1 with dual algorithm, compass, 4 gases, step back interface... I've had a VT3 since July 2010, now with 235 absolutely trouble free dives and 251 hours. I made the first battery change in the computer and transmitter only about a month ago, as soon as the low battery icon came up. The VT3 is my primary computer and I have no plans to change. I dive a Geo2 running the DSAT algorithm as backup and have a SPG on my 2nd HP port. I've been happily diving Oceanic computers since 1999. The other 3 divers in my family also dive Oceanic computers, ProPlus 2s.
I've never heard Aeris or Hollis versions have more problems than Oceanic. I guess it's possible that Hollis and/or Aeris eventually plan on updating to the equivalent of the VT4.1 to stay more competetive. Personally, I would expect to pay less for an Elite T3 or a DG03 compared to a VT4.1. If I had either, I'd probably be as happy as I am with my VT3.
Good diving, Craig
Out of curriosity, I priced all 3 current models (computer and transmitter) on scuba.com. Oceanic VT4.1 $1,005 including a $95 rebate, Hollis DG03 $890, Aeriis Elite T3 v.2 $650. Looks to me that the Aeris is the bargain here of the two older models. The newer Oceanic model carries a premium. I paid $900 for my VT3 in 2010. No mention on Aeris or Hollis website of a discontinuation or introduction of a new model.
Scuba shopping often requires careful homework