alright, here we go. This is my favourite subject cause i have a war brewing within me about this exact same thing.
so...
From what i hear, the battery life is much longer on the 9700 than the 9000. And the size of ur phone will make a difference in day to day use. The original bold is massive and it took me a very long time to get used to it. However it does have the greatest bb keyboard ever made. I think u will get used to typing on the new 9700 keyboard though. If i was able to learn how to type on my girlfriends iphone, i think it's possible to learn how to type on the 9700. The screen size is where i will not compromise. I have the original bold 9000, and i cannot go to a smaller screen. I find the 9000s screen tiny already and to go even smaller is unimaginable. When it comes to the trackpad, i think its a very nice thing as well. My bolds trackball has been cleaned a number of times which is not a good thing.
If i were u, id go to vodaphone or orange or t-mobile and id ask them if i could hold both phones side by side. Type the same thing on both phones and see how that feels. Surf the same web sites on both phones and see what u think. Which one can u read better. It's all about the compromise between personal comfort and userbility. Sure the 9700 can last forever and is small, but is it okay enough for u to type on and can u see the letters fine while reading the screen? All very tough questions.
For me, the 9000 wins. Still. The bigger screen and the fantastic keyboard cause for me, a blackberry is a keyboard and a screen, that's about it from a hardware stand point. What is a blackberry to you?
Ask your self...what will u NOT compromise on, and go from there.