I have no experience with ASIO2KS. Yet, looking at the webpage, I see that it is labeled as beta, and hasn't got any new versions since 2003.
Constrast that to ASIO4ALL that has even been tested to work in Windows 7.
Internally, they use the same concept (using kernel streaming and bypassing the windows audio stack).
About the number of blocks in asio4ks, i can only guess that it represents the internal buffer blocks (i.e. how finegrained is the whole buffer).
Ideally, one would want this to be just 2, but higher values can help to get less CPU spikes.
<[JAZ]> Pa pi pa pa pa pi pa.... ;ĚD