Need GPU help please...

Ok, so I was all set to buy the new GTX 970 FTW for my x51. But, after watching some videos I hear there are problems with making the Maxwell cards work with the R1 version. Has anyone here successfully added the new GTX 970 to their R1? Note I have the 330 watt power brick and the I7, but people are saying that the motherboard on the R1 isn't compatible?

Just need help guys, before I waste $400.00 on a card I can't use. If you agree this won't work, can someone give me a valid replacement to my GTX 660?

Thanks as always!