I recently went through the same process. I bought a .22 mag. At the end of the day I liked the flexibility of it. You have the choice of 30, 33, 40, 45, and 50 grain bullets in many different configurations. This gives you a lot of options depending on your game and the range you're shooting at. I try to stretch my dollar, and the ability to use the same rifle for many different animals helped me make my decision.
That's not to knock the 17HMR, as it's a fine round. It just didn't fit the bill for me as well as the 22 mag.