Thoughts, not experience, so take it for what it's worth.
The biggest problem I see with a .22 Hornet these days is the archaic specs that SAMMI (SAAMI?) has stuck the commercial makers with. Huge gaps between minimum chamber, max cartridge size. Makes brass get worked hard every time it runs through the dies. Not a big deal for them rich enough to be running only factory ammo, but...
If a fella were to closely match his chamber to the dies, and minimize the differences he would have a pretty sweet , mild, round, with fairly long brass life.
Of course, this runs the costs up a fair bit, having to deal with either a reamer made to match the chamber, or two reamers, one for a set of reloading dis to match the reamer for the chamber. Ouch.
I have been lusting after a .17 Ackley for a few years too. The arrival of the Hornady Hornet, has offered us the availability of factory ammo, brass and inexpensive dies made to modern type specs (as opposed to the old Hornet industry specs). Kinda sucks that the 17HH brass cannot readily be converted to 17AH. Dunno if that was by design or accident, but it does kinda result in the 17AH being a rather more expensive project. Really am considering the HH as an option now.
I have been in the gathering together stages of a Hornet based small Martini for a while. I have an action, a couple barrels (one a .17) and am sort planning a rig that I can try both out on. Project 42 or thereabouts.
One of the benefits of the .22H is that I can cast for it. With Small Pistol Primers,light powder charges, and cast bullets, it is almost as cheap to reload as a .22 rimfire is to shoot.
I think a guy needs one of each, to be sure!
Cheers
Trev