There seems to be a love \ hate thing with Tt products so you are sure to get some wide opinions. I've used 2 of the 420W PSUs and have been very happy with them so far. To be honest, I got a much better product than I expected but that doesn't mean I would fully endorse one for high end use over the long haul. It would take a while for me to gain trust in one before using it for a high wattage system, so I still still trust someone like Antec, Fortron, Enermax, etc. for the long run.
I'm using an Antec TP430 right now that I bought 2 or 3 years ago, or whenever the KT266 chipset was the hot setup. I've used it with an XP1700, XP2400, XP2800 and now a Newcastle 3800 with a RADEON9800 and the rails are still strong and stable.