Well, I've been a .17 calibre fan for many years myself, and I built a .17 Remington on a used 600 Remington action about 25 years ago. (It was formerly a .222 Remington.) I took it to Alberta for gopher trips for many summers and always felt it was one of the best calibres I ever used. High velocity, flat trajectory, no recoil, and absolutely impressive results! It has a major amount of "IVG" .... "Instantanious Visual Gratification"!
I shot it for about 1,500 rounds in the standard .17 Remington version, and then my local gunsmith turned the barrel back one thread to freshen up the throat and re-cut it to the .17 Remington "Improved" version. It straightens up the case body and gives it a 40 degree shoulder, which gave me much longer case life than with the standard version, plus about an extra 100 fps that really wasn't needed to be honest.
It finally "cashed in" the original Douglas barrel at about 2,500 rounds total and so we re-barrelled it into the same 'improved" version of the .17 Remington with a new barrel. Sadly, I haven't had time in the last few years to get back out to Alberta to try and wear this barrel out as well.
To my mind, the new .17 Fireball version should give a little longer barrel life with it's somewhat smaller capacity case, and that cartridge case seems "square" enough to not have the stretching problems I encountered with the slope shoulder and tapered body of the original .17 Remington factory cartridge.
Just my two cents worth .... but I think the .17 Fireball will be a winner with the dedicated crowd of shooters that love using smaller than .22 bores.
It tempts me ..... and I already have it's bigger brother!

If I had to list any "cons" to the idea, it would probably be that you will need dedicated .17 cleaning gear and brushes, but that's not a huge issue. You might notice a bit of barrel fouling with the high velocities, but again good solvents that are currently available should take care of that too. If you have big "mitts" like I do, reloading such a small cartridge with tiny little bullets can be a bit of a challenge, but again it's not that hard to deal with.
Hope this helps you to make a decision, but in the end ... if you really liked it .... buy it!
Cheers,
Reverend Al