E.Honda,

If the 2700+ is the BEST you can get for that board... then I would go for the Athlon. I do feel your pain in hardware upgrades. Likely your NEXT mobo/processor will be PCIe instead of AGP.. so it also means a new graphics card, RAM, and Processor.

Here is a link that describes the differences:
http://www.hardwaresecrets.com/article/127

You might want to follow up with actually checking with the manufacturer (not just the motherboard book - or even the website) of your motherboard what the MAX that is supported. Often there are BIOS updates that add more processors to the list (often undocumented other than the BIOS update notes). I would think that if it supports the Athlon 2700, it should support the 2800+ as well (perhaps more). For example,I have a socket 939 board that supports Sempron's and Athlons all the way up to dual core FX chips!!

Taxman

"Any group is weaker than a man alone unless they are perfectly trained to work together."
- Robert A. Heinlein, Starship Troopers