As great as EFI Live is, its very hard to do tuning as a profession and only own EFI. Unfortunately EFI can't always do everything on every controller but 99% of the time it can do what most GM tuning shops need. I learned years ago that I needed several other tuning software if I wanted to do alot of tuning. Im not faulting any software but its impossible for any one software IMO to the best at single thing. I will say EFI in my option is the best at more controllers than any other product out there hands down. The few things other software are better at are rarely an issue but for that 1% I have to own other tuning software. Just like I have mostly snap on tools but very rarely they may not have a tool I need and mac or some other tool company makes it. That doesn't mean snap on isn't good. Thats all just my opinion.