I have the Shield in 9mm and so far I love it. I haven't had a chance to shoot it as much as I would like, probably about 400 rounds or so through it and no issues at all. I actually really like the trigger....really crisp and smooth. If you are looking for a good single stack carry gun I would recommend it for sure. I would also recommend taking a look at the XDS. I currently carry the XDS as my primary carry gun and I think its a marvel how they were able to fit a .45 ACP in such a small frame and at the same time be extremely shootable. I plan on rotating between the Shield and my XDS as my primary carry guns depending on the mood that I am in.
Personally I like the overall feel of the Shield and the trigger a little better than the XDS, but I love having the power of a .45 at the same time and I tend to be a bit more accurate with the XDS for some reason (I also have alot more practice with the XDS so that probably has something to do with this). I was torn so I bought both
If you are looking to test fire alot of guns for cheap I recommend heading down to Ahlmans next weekend. They are having their annual shooters roundup. They have alot of venders there and you can test fire their handguns for free all you have to do is pay for the ammo. (you have to use their ammo) Last year they had S&W, Springfield, Ruger, and a couple others I can't remember.
Here is a link to their webpage
http://www.ahlmans.com/SR-Master%20Page.htmAlso see below for a pick of the Shield and XDS next to each other. Shield is 9mm and XDS is 45.