Hi Chazzbo,
I've not heard of any problems with the T series. I could be that the dealer is a Nelson Pass design fan, and is just somewhat biased against the T, which Nelson was not involved with. Jon Solderberg of Vintage Amp.com you tell you more if you have a specific question. Like Sean, I have an S350E (inbetween the S300 and S550E), and a FET 10E pre. They are excellent, and I highly recommend them. There is a very clean S300II on eBay right now for an attractive price, but I wouldn't be afraid of a T. I do think you can get more amp for the $ with an S, as they are older. Log on to Vintage and ask Jon about the amp you are looking at. Tom