I went into iron shopping last fall with the intention of landing on HMP - and ended up with Forged Tec X. My fitter reps both brands and he just doesn't like the interaction of the HMP with the turf in the area that we live. I only hit the Mizuno indoor - so I can't say I have first hand knowledge of that being an issue. I am very happy with the FTx.
I don't have any experience with the HMP's but I did hit a buddies 225 7i the other night. I have to say that it felt really really good. It was a much more solid and better feel than I typically get with my FTx. I also had a much higher launch than I typically do with mine.