I have personally used DSM 450's which were pretty good considering all I had to tune on was an SAFC, then went to Uberdata and they were better, eventually switched to RC 550cc which sucked, then precision 880cc which worked great, then went to Precision 1000cc on Crome/Crome Pro car idled and drove like stock with just a resistor box, and now I'm on Precision 1600cc w/AEM injector driver on Neptune... So far so good... Surprisingly the idle is very good (as far as a/f)...