When my converter went it took the transmission with it. Granted it was pretty gradual. When I bought my converter and valve body (trans had 10,000 miles on it) the "warranty" was 3 years unlimited milage, unlimited HP. Last I checked their web page, they didn't have any sort of written warranty.
When I started having issues with mine, I called and Joe (the only tech support person) had me jump through a TON of hoops, and the transmission passed every time, but the converter would still slip. His only response was "Send it to us and we will rebuild it. " He was totally convinced that there was an inturnal issue with the transmission, even though it would pass EVERY test he threw at it.
When it finally went I was ready to spend my money with them, even though I was frustrated. I called and called. No return call. They kept sending me to his voicemail, even though he was on vacation! At the time the truck was my daily driver and I had to have it NOW! So I turned to Goerends, closer to me, and he stands behind his warranty.
If you want more details on my issues with Suncoast PM me, and I'll tell ya. I try not to publicly bash companies. There are many people out there that are happy with their product.
Josh