if u wait for the SIS 745, u won't have as many stability/compatibility issues...also, the perforamnce should be slightly (and unnoticeably) slower on the SIS 735 using the same settings..however, it will allow the use of pc2700 memory without jacking your FSB out of control...it'll allow for asynchronous operation of 133/166 (fsb/mem), which should counter it's slower performance and in fact overtake the kt266a
and u won't even need pc2700 to make use of it...a lot of high quality pc2100 hits 266mhz no prob...as well as even the corsair pc2400 modules.
and of course, the NB runs cool requiring no HSF = less heat, less noise, etc...and they should be cheaper than kt266a boards (from ECS at least)