I'm not aware of any EFI manufacturer that's any better, from a tech support standpoint. The basic problem is, every tech support phone call tends to turn into a long, drawn out ordeal. This is because the people calling in don't really understand how it all works and the solutions are rarely simple. Every installation is different too and the tech support people need to know everything about a particular installation before they can begin to diagnose a problem. This all adds up to hour long tech support calls.
That being said, even though I have a Holley ECU, I've never called Holley tech support; not once! They have a fantastic on-line forum, just like this one! Every problem imaginable has been discussed there ad-nausium. Holley's tech people are all over it too, so you can get a quicker answer on the forum than you can by calling. Furthermore, I bought my Holley Dominator from the most knowledgeable EFI guy I've ever met. He knows my installation down to the finest detail and he knows Panteras too. If I have a question, I either e-mail, text message or call him and I usually get an immediate response. I have his mobile phone number too, so I can even reach him at odd hours, if need be.
So that's my advice. Don't buy your EFI system from Jeg's or Summit; buy it from a dealer that provides tech support. The exception is, if you want one of the Sniper self-tuning systems. It seems they either work great out-of-the-box or they're terrible, with not much in-between and not much you can do about it if it doesn't work. Buy those from Jeg's or Summit because if it doesn't work out, you can return it for a full refund; no questions asked!