the 5970 doesnt have thermal issues either at stock..
and AMD mentions that the card is very overclockable for ENTHUSIAST...which it is...enthusiast know that cooling is important and will be monitored/changed to adequately cool this beast of a card.

theres nothing "wrong" with the 5970..yea it'd be nice to have better cooling for the vrm's to withstand a higher overclock but really thats just asking for something extra..the card performs as it is intended too..and if you are an enthusiast and want higher clocks..then be one and put some water on it or wait for an aftermarket air cooler or do some modding to it..
not that u need it since it can play everything at stock clocks but if ur enthusiast u always want more and u know that u need things like better cooling more volts etc etc...
back in the day u couldnt expect 15-25% overclock on cpu's with stock cooling and volts..
l