using the palit 970 jetstream for the past 6 months, no problem. Switched from a msi 560ti twin frozr. The difference in build quality is massive, twin frozr 2 is built like a tank, card big and heavy, the palit felt flimsy with its plastic outer shell and plastic back extension. The palit 970 has a mini-itx sized pcb with a cooler that extends beyond the pcb, so they use some black plastic to cover the back.
However, I popped the palit into my system and the performance gains were massive. Once u insert it and forget about the plastic, it doesnt make any difference.
As for cooling or vrm, vram... Well palit offers a similiar 3 year warranty as the other brands that offer more extenisve cooling, so means they are equality confident of the longevity of the card. If u want more warranty, consider zotac. Their 970 cost the same as the palit, slightly slower clock, but 5 year warranty.
The only complain i have of the 970 jetstream is the location of the 2 6-pin power connector. They put it at the top, with the clip hidden behind the plastic shell. Nightmare to remove the the connectors.