tis true....it's also unfortunate how much of a hit the 3850/3870 takes when lots of AA is heaped on. Hopefully some of this will be addressed in future driver updates.
Also 1 thing to note is that performance will be a bit higher on x38 motherboards as the P35 only has the 2nd PCI-E slot running @ 4x, which significantly impacts performance. I did a test of my own and scored about 15% less in 3dmark06 using a x1900GT (tested at both x4 and x16)
Anyway for 115 shipped my 3850 512mb was still quite a good deal...I made a little promise to myself not to spend more than 140 quid at once on any single computer part. Also I mainly play UT3 and the 3850 512mb will handle that at max settings/full AA+AF no problem @ 1440x900