I work in a VZW store, and I can tell you I see a lot more 325i's back with problems. Of course, there were a lot more sold than the a870, so you'll have that. I would honestly go with 325i, BT capable, and once the S/W updates are done to the phone, battery life, reception, and clarity are awesome. But you're gonna want to make sure that it has the current S/W in the phone. Same with the a870. Plus the 325i takes a beating too. I've seen them come back looking like they were used as hockey pucks or something and still worked pretty good.
I currently own a 1st generation Chocolate (VX8500). It's been a decent phone overall, but really, it's way more than I need. So right now I'm thinking about selling it on eBay and picking up either a Motorola V325i or Samsung A870. On eBay the price is about the same for both of them, so that's not an issue. All I really need is good reception/call quality in a relatively good-looking and small form factor.
So, does anybody have any experience they'd like to share with these two phones? Any advice would be appreciated!