Okay, so I've had the Bold for a day. Here are my thoughts!
1. Size (the thing that started this thread)
I have to agree with other people on here. If you're currently a Curve owner, this thing isn't that much bigger. Here's the thing: the Curve actually looked and felt bigger than it was. The Bold, however, actually looks and feels smaller than it is. Gettit?
Sure it's a bit of a slab, but it's slim (slimmer feeling than the Curve), and only a couple of millimeters too wide. So, pretty happy there. Fits in the usual pockets. Slap it down on the table and it's just good looking enough to get away with the "oh my god that's a phone frmo 1995" first temptation based on size.
2. Form
Screen: yup, as good as it's been sold. Pictures and movies and whatnot look fantastic. Emails look good, although it feels like I'm seeing fewer lines of text than on the Curve. Blacks are black, colours are vivid, and I hope I get to use the movies past the first few days of "oh wow" viewing
Keyboard: bit spongey, but really usable. Not having the keys as clearly separated as the Curve takes some getting used to, but thankfully they have ridges so it's a pretty good experience. Already having fewer mistypes than the Curve, and it's got in-line spell checking so that's a bit of an improvement
Red Light: this is nuts. If an email comes in while I'm surfing the web, the red light is literally BLINDING. OMG, I think I'm going to have to find a sticker to put over it, it's like eye surgery as someone else said.
Trackball: Doesn't stand quite as "proud" from the rest of the front face as the Curve one did. This means it's slighlty less responsive. It also makes a scratching noise, which I'm hoping will wear down after a while.
Rest: leathery back - well, it slides around on the table less than the Curve. The size isn't as perfect for my hands, but see above, it's fine really. Pretty much everything else is much like the Curve was.
3. Speed/interface/software
Largely the same as the Curve. Black icons are nice, but having so few colours means they're less recognisable than the Curve. Style over substance.
Sure, it's a bit faster, but then my Curve never felt slow. So the improvement is like a 20% benefit to me, although it might be 100% faster.
There are a few more games, the media player is revamped and such, but nothing earth-shattering. Bedside mode is neat, but I don't really know what it does appart from turn that red blinking light off, and maybe mute stuff? I haven't looked it up yet. Maybe it will turn up some romantic music if/when I get lucky. You never know.
4. Web Surfing/3G
Okay, here in the UK 3G is making a BIG difference for web surfing. Note that this difference is EVEN bigger when using a fast browser like Opera Mini. The blackberry one, while neat, still gets really slow on some sites.
So, 3G, good stuff. WIFI? Will only very rarely use it - like when I go abroad with the shocking roaming rates on internet access.
5. Battery Life
Been amazing for me so far, as good as the Curve. Maybe as I'm in London and it doesn't have to search 3G so far, but 24 hours of pretty solid use, including calls and bluetooth and so on and it's only down to 40%
6. Conclusion
Okay, I'm glad I upgraded. This will help me do the stuff I need to do on the road (email and web) quicker and better, and maybe I'll get to enjoy some of the media stuff aswell. It's not like the most amazing step change I've ever experienced in an upgrade (like the first colour screen mobile - ah, those days), but I'm lovin it so far. Just, as it was really quite expensive... a 3G Javellin would win obviuosly, because the handset doesn't need to be this big, but that will have to wait.