I use hold a LOT when it comes up, because I'm ALWAYS mindful of it. I use it to "smooth" my stack, and deal with the RNG dealing me awkward blocks - which tends to be often enough. Usually every 1.6 pieces on average, I hit the Hold. Watch me (omio) on TF, you'll notice the same trend - I hold a LOT to avoid awkward block pairings.
I have no idea about the number of times I use the hold feature each game I play, but I use it as often as necessary. I confess that if I played the GB version of Tetris again, I would have a tough time adjusting to not having this feature.
