I'm planning to buy a new harness and I'm not sure what to get. I'm eyeing on three brands the hollis HTS2, diverite transpac or OMS IQ. Can you guys help me decide?
A bit tough to determine if I / we can help you decide, but maybe I / we can offer personal experiences and/or observations.
The decision criteria should be based on a) what YOUR preferences are in a rig, and b) the type of diving YOU intend to do. It would also be helpful to know YOUR reasons for narrowing the choices down to the three particular units you mentioned. My criteria for harness selection primarily involve simplicity, flexibility / adaptability, and buoyancy characteristics (the less inherently positive, the better). Therefore, of the three, I would select the Transpac, in part because I have personal experince with it. I removed all the padding from mine (shoulder pads, lumbar pad), and find that it works for BM singles, BM doubles, and SM doubles, so it meets a variety of needs. It is still a 'soft' BP, and is inherently positive. But, with a couple of tanks, that isn't a problem. It has shoulder quick-release on both sides which some view as unnecessary and a possible 'failure point' - not a serious cocern for me, but it may be for others. The Transpac fits me well and I have no real complaints. I don't particularly care for the IQ because I don't see that level of adaptability - I don't own one, but I have used one. I just don't find the IQ to be something that fits my notion of simplicity it seems a bit 'cluttered' to me. Some posters may give a negative critique of OMS products in general, but I won't. I have a couple of OMS BPs, and one OMS deluxe harness, and have been happy with OMS gear. I have no first-hand experience with the Hollis, other than reading good user comments about it - people who own it appear to like it.
One question that others will probably ask, so you might want to get it out of the way early, is why you are not including a 'hard' BP / harness setup in your potential choices. The Transpac comes close to that, if stripped down and all the padding removed. But, a simple metal BP with a single piece web harness is not a bad choice, either.