William - per your criteria the 17HM2 (or 17HMR) is the ticket if bug holes is your goal... no 22LR is going to shoot more accurate than the M2. The ammo cost is less than half to a third with the M2 verses the 17HMR, but the Hummer easily buys you 2-3 or more times the range on the other end. The M2 a fad? Not to me, but unfortunately they didn't catch on as well as the 17HMR did, so many makers stopped making firearms for them. Too bad, they are an easy choice over a 22LR for anything. The 17HMR might be overkill for your uses (besides costing more to shoot) because you start shooting them at 100 yards and go way out from there. At the first Digger Wars I set 150 yards as the minimum range for a shots, rifle and handgun centerfires, and when the 17HMR came along they too had to start at 150 yards. In 2003 I subtitled that 10 days shoot "The Year of the 17's", and even though everybody showed up with all their 17 wildcats, they also brought their 17HMR's (most had at least 2 of them), and it was the 17HMR's that got shot the most.
RE all the comments so far... comparing the 22MAG to the 17HM2 is about like comparing it to the 22LR, a comparison not on the same page. The comparisons that make sense are 22LR/17HM2 and the 22MAG/17HMR.
comrade - The 22MAG does not outshine the 17HM2 for tree squirrels, in fact the M2 is the optimum choice for tree rats over any 22RF. Fine if you want to blow them up, or for ground squirrels, but not if a squirrel you want to eat. As for coyotes, as above not a valid comparison to the M2, but add the 17HMR to the mix and the 22MAG takes the back seat again. Shot placement and hydrostatic shock with the 17HMR more than make up for the difference in bullet weight of the 22MAG.
mechanic - keep in mind that naysayers obviously have no experience with the 17 rimfires pard.

I actually have pictures of dimes shot with one of my 17HMR's, the 1/4 MOA one. Only at 100 yards, but one with a three shot group in it makes it obvious at 150 would also be doable.
I base my opinions on long expereince (longer than anyone else with the 17HMR), the 17HM2 from having owned 3 of them (still have 2), and the 17HMR's from also owning 3 of them (still have 1), including the first privately owned AND that was the most accurate of any of the others it ever shot beside - lots of them. I wasn't a paper puncher, I was a hunter, but it did 5-shot 100 yard groups in the high 1's to very low 2's the day I sighted it in at 100 and then out to my chosen PBR; and my #2 Hummer did the same in the mid 2's, so a dime would be child's play consistently with either of them. I took small game well past 300 yards with them. I lost track of how many 1000's of rounds I shot in them, probably between 15K-20K. And after sight in all of that for longer range ground squirrels, jackrabbits and quite a few predators, including several coyotes past 200. So I think I have a pretty good idea from experience what the 17HM2 and 17HMR are capable of on paper and flesh. They worked so well for me that they retired all of my 22RF's in turn soon after each of the carts came out.