Interesting... Better than a good .22?Uuuh, no.
Nothing is better than a good .22, although lots of things are better suited for a particular task. I like my .22s, but they're not much good at 100 yards, and not much good past that, where I'm learning that the little .17 HMR is good out past 100 yards, even out past 200 yards for some types of shooting.
The .17 HMR is a necked down .22 magnum case stuffed full of L'il Gun powder. The 17 grain bullet leaves that barrel at something over 2500 fps. On my deer lease, it's fashionable to take a .17 HMR to the stand to watch over the food plot. In the absence of venison, a swamp rabbit is liable to sun himself amongst the greens and the .17 HMR can take him at ranges that might prove inconvenient for the .22 LR.
Also, that little .17 caliber bullet is very frangible. It's going to disintegrate if it hits anything. I've talked about the over penetration of the .22 LR and the .17 isn't capable of much penetration with the varmint bullet.
The short answer is that it'll never replace the .22 LR in my battery. It also won't replace the .243, or the .30-06. However, if I'm asked to snipe at crows, or if I'm forced to do varmint work when raccoons are depredating the muscadines, I'll probably pick the .17 HMR. I know that it's fast enough to do the job and I know that the bullet isn't going to ricochet into the next parish.
When I'm squirrel hunting, I'll take the .22s. Nothing much beats a .22 LR for the squirrel woods. The .17 is a caliber I'll use as a step between the .22s and the .243s.
But no, nothing is better than a good .22.