There is a fine line between too big and too small. Smaller is better these days and that is a big concern of mine so I know where those who are concerned about size are coming from but... most Blackberry users want a decent screen and a good keyboard and that doesn't fit into a tiny form factor.
To give you some background, I had a Pearl and it was great to carry around. It felt solid but the battery cover creaked and was annoying. For me, it wasn't long before decided I just couldn't handle the keyboard and Suretype. I was actually avoiding replying to emails with it so I decided I needed to change. I went to the Curve and it actually felt a little cheaper than the Pearl. Maybe it was the colour but it felt too "plasticy". It was much better for typing (sacrificing size) but I tended to use my fingernails to type and I wasn't too fast with it because this was awkward.
I also looked into the 8800 series at one point and held one briefly. I never got around to coming up with an impression of how solid it was because I knew it wasn't for me. While the keyboard was bigger and again I would sacrifice size, I said, "no thanks". Compared to the Bold, the 8800 series is about the same size but it felt like a box. Because of this, it felt bulky so I never went down this road.
I had mixed feelings about the Bold so I thought I would check if there was a demo unit to hold. Rogers does have a display unit that is the same size, material and weight but it's not functional. It felt solid and light at the same time. Because of the fake leather backing, it doesn't feel "plasticy". I'm sure that the silver rim around it is stainless steel and is not like the top of the Pearl which chipped right away for me. I'm not about to take it apart to check
The Bold is aesthetically pleasing both in form and in function. The screen is not counter-sunk as older models and the buttons have a great feel when pressed. If you've had a Pearl, you will notice that the trackball is exposed less and it actually works better, once you get used to it. It's position allows you to glide across the top as it should be used. I think that because of this, the trackball will wear better and have less issues. I guess we'll find that out later.
Anyway, even after I held it the day before launch and was impressed by its construction, I still wasn't sure I wanted the Bold because it felt a little too big. Curve size would have been perfect but that was before I actually used it. Let me warn you that you can't get a feel for the Bold by holding it in the store. You have to actually use it. Now that I have the Bold I find that with the curved back and edges of the Bold, it's still the same size as the 8800 series but feels smaller in your hand. It's more natural as your fingers wrap around the device to support the back of the phone so that you have the stability to be able to belt out those emails. With the Bold you use your finger tips to type and it is much better for natural typing. It is also as solid as the demo unit was in the store.
Combining the keyboard, excellent screen and functionality of OS 4.6, the Bold is the smallest you will get with the best in functional screen size and keyboard. I think that most will come to love the keyboard and as soon as you watch a movie on it, the screen can't be big enough. You will probably give a little in the size department when you actually use one. I've had many Blackberries but this is the first time I can say that this thing IS the smallest, almost fully functional computer that can fit in your pocket. And look, they threw a phone in too!
Hope this helps,