refrigerant leak detection instrument

I am an test instrument geek (but more in a lab than in real world) . A friend of mine has a repair shop and has asked me to help him select a new leak detection unit. He had been looking at the Inficon T-Dek unit a unit by Field piece and two from Bacharach (H10G and H10PM). Can anyone tell me if he was on the right track or if there are others (or another) you would recommend? I can do the performance analysis based on specification sheets- but would really like some real-world input from real users- any help would be greatly appreciated.
I just got a recommendation on another site last week and bought an Inficon Tekmate. I learned that there are two types, but I don't remember what they are. This one is of the more modern type. It cost $185 including local Texas sales tax. It runs on two D Cells. If your friend will be using one a whole lot, maybe a similar unit with rechargable batteries might be a better choice.

I can only offer anecdotal evidence on this unit, but it was really impressive. It picks up a 1/4 ounce per year leak and allowed me to home in several leaks in very short order. I guess the most impressive of them was that I had a leak in the condensor that I detected by simply putting the nose down in the shroud area. It was sensitive enough that it picked up the leak without having to go directly to the actual leak.

The unit comes in a blow mold case with a place to hold the batteries. Since I don't use it all the time, I like this because I can put the batteries away so that if time drifts by to a point that the batteries leak it won't ruin the unit. Also in the case is a bag with 10 extra tip filters.

Inficon is a name in the industry that I've heard lots of good things about and my new unit is one of the best tools I've bought in a long time.

Hope this helps,
Doc
You might want to hold off in making a big investment in a sniffer right now. We are approaching another complete refrigerant change to R1234yf in the near future and there is going to be a bunch of new equipment available that will work on R134A also.