You can always get a sense about good shops, and shops that are just there to sell you a bill of goods (hence the reason I do most of my vehicle maintenance/repair myself, except for powertrain). EGT is definitely the former - excellent service, inform you of their findings in a timely fashion, and don't try any hard-sell tactics. I had a leak in the Trans or Transfer Case from some hard 4x driving over the weekend. Turns out the Trans likely just overheated and oil vented. EGT indicated no real issues found, but fluids were a little dark and could be changed. I had them service both the Trans and Transfer Case, since they already had my Tahoe. Reasonable price, and saved me the hassle of doing it myself (since Chevy refuses to put drain plugs in the Trans pan, which makes for a mess).