No, i'm not so sure it's just me. I did a quick research, and yes, the 3100 sempron has the intergrated memory controler that enhances the chip's performance. Therefore, on the benchmarkings of memory intensive applications/tests, the 3100 sempron does quite well. However, on other benchmarking tests, it leads xp2600+ by only a small margin, and is similarly tested in certain benchmarks with P4 2.4. If you compare xp2600+ or P4 2.4 with my overclocked mobile..., well there would be no comparison. In addition, although the articles did say that the decreased cache is not a real big factor, the 3100 sempron still only has half the L2 cache of a mobile xp. Therefore, your claim of "very significant performance advantage" is a bit of an over-statement.
I hope you don't get all bent out of shape over this. I've seen just too many threads where people make personal attacks and threads get crapped for differences in opinions. I am not trying to thread-crap or anything. I am merely offering an alternative to those who are not aware. It is a fantastic altermative as almost all overclocked mobile xp2600s can get 2.5gigs on AIR. That's 500Mhz overclock! That's 25% overclock over its original 2.0gig speed. I run 200x12.5 at 1.725Vcore Prime95 stable. Nonetheless, 3100 sempron seems to be a nice chip as well. They say it, too, overclocks very well. Not sure how much though. Anyway, thanks to you and to this thread, I learned a lot about 3100 Sempron tonight.