I had been messing around with W3 Total Cache trying to speed up my WordPress site. First Bytes were horrible with it though (normally between 3.5 to 4s) with W3TC installed. Deactivated that to try Quick Cache... and now, First Byte test come back 0.4 to 0.6s! Overall Load Time is also a little better, but the initial aspect is WAY better! Also, I'm hosting on the GoDaddy 4GH Network... so... nice. This was with their default settings btw... haven't tried playing with them yet beyond the standard.