Tl;dr: I own the HMR with aftermarket upgrades. Don’t buy the HMR Pro. Buy a custom gun.
Agreed that you should stretch a little further and go custom. I have the HMR and have put a TT and the Premier bolt in it, so I’m creeping up on the HMR Pro cost at this point, and I replaced the barrel with a Hart so actually I’m well over the cost. The factory barrel wasn’t nearly accurate enough, even over 5 shots.
It’s a fine gun if you don’t think you’ll ever burn out a barrel, but rebarreling them is a pain because of the coned breech. Many outfits won’t do it, although some will; it’s just a bit of a pain and you can’t use any of the discounted barrels that crop up on here regularly. The ergonomics of the stock are actually excellent for a factory rifle, especially with some minor modifications, but you can’t run mag-length rounds because the mag well cutout in the receiver isn’t big enough.
My action is plenty smooth, and the swappable bolt faces is a really nice touch on the Premier bolt. The Premier action is also stainless, which I prefer for a hunting gun because it’s much more corrosion-resistant.
There’s a lot to like about the HMR, standard and especially Pro, but for $1600 you’re far better off saving up another month or two and buying an off-the-shelf custom gun. You can build yourself too, but if you’re gonna do that you’ll have to spend time waiting and hunting to get under the cost of a full build. Trigger, scope rail, stock with bottom metal, barrel with threaded muzzle will add up quick.