I have a friend that is partners with Blackberry and gets all the new products on the DL. This is what I have noticed with the new 8300. I can't wait for At&t to come out.

1) Build Quality.
A massive improvement. One of the best surprises of all, as I was hoping for better fits in areas like the battery door, main body, etc. This is the way that the 8100 and 8800 should have been designed and built. Having both of those to compare the 8300 with the difference is shocking. Night and day. I would rate them in the following order from worst to best. 8100, 8800, then a giant improvement to the 8300. It's as though RIM finally got serious and listened to the public regarding looseness, noises, etc.

2) Ergonomics
This BB is extremely nice to hold and feels extremely secure in ones hands. The other aspect of the ideal shape is that no matter what you hand size it's like the magic combination. Everyone that has tried mine is amazed at how nice if fits in their hand. The rubber sides are a really big improvement and draw positive responses from people that try it out. Having a more rounded shape on all surfaces lends a certain amount of comfort that simply does not exist on earlier models.

3) Phone Function
The phone is truly clear and warm in tone. The clarity is very refreshing and encouraging. It proves that it is indeed possible to have a really great phone paired with a device like this. While the 7130, 8100 & 8800 are quite close, and very good, this 8300 is a significant improvement. This is something that easier experienced that described as none of the prior three models noted here has anything less than a very good phone. So it's really a matter of experience to be able to notice the difference.

4) Connectivity
Being able to choose what you want connected is a huge asset, at least for me. To have the control and be able to turn off the email, or turn off everything but the phone is a really nice feature. It enables me to "get away" of the "sometimes" nagging alerts due to the high amount of email traffic we all techies experience. Even though I could use the phone only profile in the other models, this is just different and very welcome. A perfect weekend solution. Also because of the overall size and how thin it is, it fits in my pockets quite easily which is a real advantage as on the weekends I'm not into wearing it on my belt. Nor during the week for that matter.

5) Keyboard
Being one that admittedly is very picky when it comes to keyboards, this one is a real winner. Again it may be just me, but I find it ideal. And it's important to note that I'm also a big SureType lover and second in line behind this model is the 7130c (for me) as I can really type fast and accurately on that one, as compared to the 8700 or 8800. However that said, I do find the 8800 the second best qwerty (since the 7290) and I have no complaints with the 8800 keyboard, it's just not quite as good as the 8300.
When I compare the 8300 to the 8700, now THERE is a huge difference. The 8700 is dreadful, the key shape is all wrong and the tactile feedback is terrible compared to either the #1 8300 or #2 8800. Even though the keyboard size of the 8300 is quite a bit smaller, for me that just proves how important key shape is. some people have moderately large hands and would find the small qwerty on the 8300 very, very easy to use.

6) Camera
The best on a BB so far. Another feature which qualifies this phone as a great weekend phone. There is lots more for everyone to explore in this area.

7) Media Player
This has an interface more iPod like in terms of simplicity of controls. Feature rich, this will keep me exploring for awhile. The ability to drag and drop, is fantastic. A huge improvement which brings it to a more contemporary level. Ease of use is improved, and the degree of functionality is quite significant There are many things that can be done and it will be fun to discover everything that's possible.

8) UI
Leaps and bounds better than anything we have had in the past. Again an area that will provide hours of fun exploring and learning. Just like prior BlackBerry OS's and incremental improvements, this new version is truly valuable as not only does it expand what we can do, but without sacrificing reliability and the legendary stability of the BB platform.

The 8300 is further proof that one cannot go wrong with a BlackBerry. I'm so glad that I tried all the other brands and models. As without that experience I would not have the experience background to identify this as the World Class Device it is.

Cheers
Mischa