Ammunition supply, in my area at least, has been very spotty, quite often unavailable, although it is getting better. When it is available, it is expensive. I prefer the .22 WRM if the .22 LR isn't enough cartridge. Just my opinion.
if 22lr aint enough, 223 aint too much. The .17 is perfect for crows and prairie dogs, to 125m or so. Very flat shooting, with a flat "crack" of a blast, sound doesn't carry much, and bullets break up well oncritters, or on dirt if you miss. Way too specialized and expensive, in my book.
If you were 'normal times' backpacking deep into the Sierras and you wanted something for pot hunting that was really light and more powerful than a .22LR, the .17Mag is probably a good way to go.
For such activity a Chipmunk child's rifle that weighs about 2.5lbs and chambered for the round is a good choice. These little rifles are very popular with backpackers for their light weight, their ruggedness, and their excellent accuracy. The Chipmunk can be had in .17HMR, .22mag, and .22LR.
The majority of the weight of rimfire ammo is the bullet. Pound for pound, the .17HMR smokes the .22LR in both light weight and power. For instance, a .22LR high velocity round with a 36gr hollowpoint weighs 51gr total, with 15gr being the casing and the powder. The .17HMR can be had with a 17gr and a 20gr bullet.
In power there is no comparison. The .17HMR ammo doesn't weigh more than a .22LR but it is WAY more powerful.
In a situation like that were you need to be as light as possible and all the ammo you have or will get is what you bring with you, the .17HMR makes a lot of sense.
The ammo is readly available where i'm at, haven't done much on pricing it yet. Basicly just looking for something that's alittle more powerful but about as cheap to shoot as the .22's. use for both hunting and plinking..
The .17 is a fun round. But, IMHO, if you have a .22 WMR, I don't see any reason to get it unless you just want it. Last I saw too, the .17 ammo cost more than the WMR, but that was when it first came out, might have changed by now.