Perhaps in your experience. I just have bad luck with the newer amd products. I used to stand by amd and their whole product line, but after they bought ati, all the cards I've gotten have burned out within 6 months of normal usage. Granted all the problems I had were with heat issues, I still won't recommend them until proven otherwise. A good friend even gets me massive deals on amd cards, but I can't in good faith support them at this time.
I generally order, test, and use about 20 video cards a year in different machines (not 20 cards total, 20 DIFFERENT cards) and so far the nvidia gtx n series has been the most reliable in terms of performance and heatsinking. Oh they're pretty quiet too, except for evga's version of the gtx260 (non OC'd), that card is really loud. Lately evga's been doing well for itself with the nvidia line. Oh, and I also tend to recommend intel lately on account of the core 2 quad and i7 lineups. considering amd and ati are the same company, I choose nvidia for intel setups.
In the end, all I can offer is personal experience, take it as you will. GL lazer. Oh, if you do get the 4890, there are some pretty nice aftermarket turbine setups you can replace the stock heatsink with. Just make sure you get it before it breaks, haha.
thanks for reminding me grix.