We have used the Bacharach's Leakator10 for years now with no problems what so ever, you also have to realize we use these gas leak detectors 8 hours a day for 5 days a week and we replace the sensors maybe ever 2-3 years and it is easy to replace the sensor. We have 5 Leakator10s in our burner room.
You need to consider the calibration span of the meter you are looking at. The TIF 8800a is calibrated to sniff 50 ppm of methane. The TIF 8850 sniffs 500ppm methane and the 8900 sniffs only 500 ppm methane. Compare that to the 20 ppm methane for the Bacharach Leakator 10. Since many homeowners can sense 1-2 ppm esp. in these tight houses, 500ppm ain't much. You can miss a low level leak that will trigger a callback. Also, most of these sniffers respond to dozens of various hydrocarbons including pipe dope and leak detection fluids so you can get false positives.
Gas Suppression System Design, Inert and chemical gas system installations. We are not tied to any one of the proprietary suppression or detection products options, but can supply and have an in-depth knowledge of all of the leading systems.
I had the Bacharach Leakator 10 for many years and it served me well with no complaints. This past winter it started acting weird, and potentially would cost me 2/3rd's the price of a new one.
So I did some homework, and purchased the eL-320 from Accutools (same company that, makes the Blu Vac Micron gauges). It is very compact and light, and has worked great on the several occasions I have used it so far.
Let us know how you like the EL-320. I bought the UEI DM200 (yellow bluvac LTE) and am considering the scale and charging unit from them. Hard to find many reviews on their stuff other than the bluvac.