I drove all the way from Southern Ontario to Washington DC to get a BB tune done in person. Every cent spent was rewarded ten fold. I was grinning all the way back and even took a detour just to make the drive longer. One word "awesome"!
Added:
Stock 98 Tahoe with 257k on the clock. 265/75/16 when i got the tune done, subsequently gone up to 285/75/16. No change to my driving expereince. POST tune, normal driving Gas milage is better i.e. when NOT towing but dropped a 1 KM per Liter when towing (i.e. PRE i got 6km/litre POST 5km/litre aprox). i gathered that this was due to the early downshift (i requested this specificaly) and staying off the OD for a extended period, however i am very happy with the towing characteristics POST tune. The shift is seamless when towing but is noticable when not towing.
Hope this helps.