my feelings about x38:
1. chipset more hotter than p35, which means need better cooling on ur NB.
2. need more vNB to achieve 600fsb+ than P35, might be >1.85v
3. ddr3 overclking ability seems a little bit worse than my Asus Blitz Extreme, maybe it's bios issue 'coz it's not finished yet.
4. better inductor/mos than Blitz/Premium, that's a good sign.
5. overclking failure to restart need to be improved. now I need to shutdown my psu and wait until the 5v standby is gone to fire up the system ag.
6. much more ddr3 tweak option. will check if there's any performance gain today.

and I'll test with a 500fsb+ Quadcore and 2900xt Crossfire today to see if any improvments.

the same E6850 on my blitz = 562fsb max on air and 557fsb benchable.
might be the reason of only 2.0v vPLL on blitz.