This seems like a weird question to ask about a "phone," but which Blackberry's are best for actually using them as telephones?
Verizon is my carrier. I currently have a year old Palm Centro. It's fine for texting, emailing and is somewhat adequate for internet browsing. It fits nice in my pocket, has been durable, but just flat out bites as a telephone. I actually carry around an old LG flip phone (so old it doesn't even have a camera) for making important phone calls. When I do get stuck on the Centro, I usually have to turn on the speaker phone if I want to hear the person on the other end of the call.
My wife has had a Storm and now has an Incredible. Both have all sorts of exciting features, but I've found them also a bit lacking as telephones.
Yes, the volume on the Curve and the Bold is just fine, I've never had a problem hearing someone on my BB, unless I was in a REALLY loud environment.
I have a part time job selling phones at a large retail store, and whenever I need to call one of the carriers, I don't even use the land line phone we have at the desk, I pull out the 9700 we have setup as a demo and I call on that, way better volume and call quality. Out of all the demo phones we have (mostly Android, one BB, one WINMO) I always reach for the BB when I need to make a call.
I have used the bold and it is great for phone calls...volume is good in earpieces (but I have found some earpieces are way better than others...so I don't think that issue is directly related to the phone).
Go to a retail VZW store, and try it out. They will be usable units, and see which one you like the best. I love the bold for texting, and bbming, it has a incredible form factor. It just "feels right" in my hands. But i only use about 45 minutes of talk a month, so I can't really say about the actual phone qualities of it.
BB's I've physically tested against in the same areas on the same day
9630
9000
8230
Phones I've tested compared to my 8330 for phone calls
8830
8310
I love my 9630 for everything, but when it comes to actual phone calls, my 8330 will last longer in low service area's before dropping out, and sounds more clear on conference calls
I think a lot of it would have to do with the network and area that you're in (signal wise), but I've had a number of BB's over the course of my life/career and haven't ever had any issues with call quality, sound quality or signal (unless in remote or underground areas).
Important to note that I've probably been through about 30-40 phones over the years so have seen my share of junk phones
Here is my question....What's a telephone? lol. The Bold 9650 is good for both texting and phone calls. I had the Storm2 prior and the texting for me was not all that great.