Well, the drawbacks for me have nothing to do with power delivery or percieved lag, and everything to do with my own ideas of how likely that design would be to fail prematurely (and possibly catastrophically). I mean, imagine you are cruising on the highway at speed, and the oil line lets go and starts spraying your left rear wheel with oil...that's got disaster written all over it. Or for instance, look how much more susceptable to picking up road debris and water your wastegate is in that location. Imagine you catch a speed bump just right (not a stretch really, I do it in my Altima all the time when I have more than one passenger, and it's only 1.5" lower than stock) and damage it, now it's not controlling your boost at all, but you don't realize it until it's too late. I've got a good friend that just graduated from UTI in Orlando that actaully saw a wastegate fail on one of the STS GTO turbo systems. Spiked the boost up to 30psi and blew the dipstick right out of the hole. Supposedly it ran fine after that, but I suspect that owner's troubles are just beginning...