The Valentine had the IR scanning replaced with T-70 recon so it could be used in tournaments. The IR ability is bugged and therefore banned in most tournaments.
As for the IRHT, were it some sort of overpowered god unit one would expect to see it more in high level streams. Sure, it's useful, but if the game's top players almost always spend their resources elsewhere I doubt it's a game changer.
You do in team games. It's 1v1 where it is a rarity.