I get my tank filled at the Mission Viejo Sport Chalet almost every week. When they quit doing wet fills, Jim (who I believe has been diving since the 60's) told me the water didn't make a difference and showed me the article supporting that stance. I also heard from someone at Sport Chalet that many of the water basins in the stores were old and breaking down, and clogging drains are a problem, and they (they always being Corporate) didn't think it was worthwhile replacing them. I'll give them the benefit of the doubt and assume they're not replacing them because they truly believe wet fills don't make a difference, not because of the replacement costs.
I have an E8-130 tank that I use with a yoke regulator. I noticed 3000 psi fills would net me around 2600-2700 psi when the tank cooled, however the 3000 was on their gauge and the 2600-2700 has been on my Scubapro mini pressure gauge. I haven't taken the time to hook up my own gauge while the tank is still hot. Jordan at the MV store suggested I give him some extra time to fill the tank very slowly. That particular fill took 40 minutes. The net result was close to the same as their typical fill that takes about 20 minutes
One week I took my tank over to Sea Stallions. They did a wet fill (for $6, ouch). The compressor was already pumped up from another fill they just completed, and my tank had about 1200 psi in it already. That fill took only a few minutes, and the tank was noticeably cooler on the outside from being in the water. The net result was still, about a 200-300 psi drop.
I've figured out my own easy little trick for a full fill. I unscrew the yoke insert on the tank valve before taking the tank in, and let them fill it as a DIN to 3442 psi, screw the yoke insert back in, and wind up around 3100-3200 net. I can bleed it down to 3000, or leave it alone which is what I've been doing. I don't think 100 or 200 psi extra on my Atomic reg. for a short time will do much harm. At 3000, I have 119 cf of gas and always seem to be the person coming back with the most air. Wish everyone had a bigger tank!
The above is just my experience, not necessarily a commentary about Sport Chalet. I go there every week, have enjoyable conversations with the dive staff while I'm waiting, and sometimes get free fills too. Their late hours make it very convenient as well.
Kevin