I use them on both of my trucks, my motorcycle, and the wife's car. Oil samples are $28 for your standard SOAP report. You can pay to have other tests run if you wish. I like that they charge you when you send in the sample, not when they send you the bottle. They're also generous with sending new bottles when you ask for them and I've got 6 sitting in the shop ready for when I need them.
Is there anything specific you're looking for out of these analyses?
1996 Western RV Alpenlite 31RL Augusta
1999 Ford F-350 XLT Crew 7.3 Powerstroke, ATS torque converter, Edge Products Juice Box