If you intend to go for H1B stamping (anywhere) and like maxpayne said, "If shit hits the fan, there's still tps entry for you", you will be returned from POE if you use your TPS AP (if your H1B application is pending or denied for one reason other), at that point you will be left to sit and wait for H1B stamping. However, that being said these days H1B approval is 80/20 ratio, which means you will be vetted during petition approval more so than when you go for stamping. On top of it, if your name is not (common) one in red list you should almost get H1B stamped without any issues.