"didn't they strip out half of the L1 cache from what was on the AthloXP?"
From what I've read, it is a "pure" Athlon XP. If you didn't check the links above, here's a couple of clips from the Tom's Hardware article:
"AthlonXP becomes Sempron without any changes..."
"As the Sempron birth is nothing else than a simple renaming of AthlonXP, the consequences for customers and motherboard makers are small. If you don't mind your motherboard displaying AthlonXP at boot time, you don't even require a BIOS update."
The Sempron 3000+ (2000mhz @ 12 x 166mhz) actually has 512k L2, so it's based on the Barton Core...roughly equivalent to a 2700+? Check this CPU-Z pic:
http://www.amdboard.com/sempron_3000.html
Asus A7N8X-X
1800+ @8x210mhz
512mb PC3200
Ti4200/8X 128mb
WDC 60GB