I had the choice between the two and went with the 3AT. I've never shot the P32. I shot the 3AT for the first time this past weekend, and I posted a range report in the autoloader discussion board, along with pics. My impressions are that the 3AT kicks like a rented mule compared to my SA Champion .45. Honestly, after about 20 rounds, it's not very enjoyable to shoot. I put 120 rds through it, and that was enough for one session.
That said, it's not a range gun, it's the lightest .380 pocket pistol on the market, so the recoil is to be expected. I won't be putting 120 rds through it in a defensive situation, so I can live with the recoil in order to carry it in a jeans pocket unnoticed. I'm getting a Handall Jr. grip sleeve and putting the Bersa finger extensions on the mag, which ought to help some. That, and some practice and I think it'll be good.
Accuracy was very good at 7yds, it surprised me for such a little gun with not much in the way of sights. Check out the pic of my target in the other thread I mentioned, and you'll see.
I looked at the 3AT and the P32 at the local shop and compared, and they are just so similar in size, I knew I had to go with the larger round for carry. I've already got guns I like to shoot at the range, so once I get this one set up the way I want, I doubt it'll be shot all that extensively.
For more info, check out
http://www.ktog.org/cgi-bin/yabb/YaBB.cgi
Or, go to mouseguns.com, and click on the "semiautomatics" link, you'll find a ton of review and write ups on both guns.
Here's a good link to some ballistic testing for the P32:
http://www.goldenloki.com/ammo/gel/32acp/gel32acp.htm