With a stock intercooler there is no difference at all. If you had a combo that was maxed out and limited by the turbo size the 44 would squeak out a few more hp but that would be when running them hard. If your under 120mph in the quarter there is zero detectable performance difference. Keep in mind they could have 1 of several ex. housings which will effect spoolup and mph potential. Most likely a Precision .63. Some may have a Garrett .63 which is a winner with a stock converter. Others may have a Garret .82, Precision .85, or t-netics .63 or .82. For a sock converter the Garrett is the only way to go imo.