No-spin response
Prepare for a small boatload of responses telling you to consider a P-32 from Kel-Tec.
I had the same decision to make. I ended up going with the Beretta, because in my research I saw that some Tauri mouseguns (at least early models) had problems with the slide cracking. However, you know how it is; somebody gets a lemon and then curses a given make/model of gun at every opportunity. So one has to take that into consideration as well.
I went .22lr, and you can find reports of poor performance for either brand of mousegun in this caliber. Some specimens work great with certain ammo, and some work great with whatever. Some respond to fine tuning, some don't. It really seems to be a crapshoot, at least with .22lr. Fortunately, mine seems to function fine. Still, with no extractor and the mousey ballistics, it's clearly a last-resort or very-low-threat gun.
The cost is comparable, probably close enough to not be an issue. I think ultimately it will come down to aesthetics for the average individual. The Beretta is slightly smaller; the Tauri tend to hold one round more than its Beretta counterpart. I personally like the way the Berettas look a little more.
One last thing; consider the Beretta Jetfire (model 950 BS, I believe). Just about everybody who has one seems to love it. If I had been going the .25 route, I'd probably have gotten this. Very small, and apparently very reliable according to reports I came across. It's single action (if that matters to you). You will have to buy used, but I don't think one should be that hard to find with how successful the P-32 has been and all...
Good luck...
-tubeshooter