I lived this decision-making process over the last couple of years, including buying a 452 Varmint in HMR. First-off, CZs are gorgeous...17HMR is a wicked-cool rimfire round. Period. I want another HMR one day, and hope it IS another 452 Varmint. However, for me, the bench mark for small game hunting (for my needs) is, and was, groundhogs. Varmints, nothing I had plans on eating. I zapped groundhogs all summer using the HMR and was less than impressed with it's effect on these big rodents. Yes, it put most of them down cleanly, but not all of them...and very few hit in the boiler when I tried to achieve this mystical 150+ yard shots on them. Hunting hilly ground, you're not always offered broad-side shots, sometimes your only angle is top of the back, etc. HMR was just not that consistent a performer...in spite of how much I wanted it to be, and how much I loved the rifle.
So, as I think someone else had said..."define small game". Having seen what HMR won't do on groundhogs, there isn't a chance I'd ever try to pop a coyote with one...though I doubt they're as tough as some of the groundhogs I've shot.

The only Ontario hunters I've ever talked to who love think they've found the perfect rifle are rabbit hunters who like the challenge of longer-range, head-shots. Maybe a crow here and there.
Not willing to give-up on rimfires, I played around with a .22WMR (much better on groundhogs) but then quickly moved to a .223 and it's been awesome. .204 was a temptation, but .223 ammo is just more commonly available, and there are some deals out there that rival HMR cost.
HMR really is a niche caliber in my way of thinking~barely enough for groundhogs, too powerful for rabbit or squirrel body shots, etc. Remember, I still said I want one, and plan on getting another...but the reason one currently doesn't sit in the collection is the lack of usefulness, not the ammo cost.