I have never owned any TFOs so take my opinion with a grain of salt, BUT I have handled and shot them. I also have friends that have them and have given reports of their durability...and sometimes the lack there of. The HDs seem superior for MY purposes. My XD gets banged around a lot. It is a duty weapon and a CCW and is rarely sitting in a safe....actually it is never sitting in a safe. The only break it gets is on the nightstand while I am asleep. I hear people saying that the TFOs are more sturdy now than they have been in the past. That may be true. I simply just can't afford to risk it with my XD. I know I can trust the HDs to stay strong for many years to come. They are very solidly built, to the point I have no problems heel-racking the slide in a "one-hand" scenario. I wouldn't feel comfortable doing that with the TFOs. They may in fact BE as sturdy as the HDs but I simply don't trust them. I NEED to trust my pistol all the time, everytime. For that reason, I recommend the HDs if they are going on MORE than a range gun whose purpose is soley for entertainment.
TIFWIWWMNBM (take it for what it's worth which might not be much)