Opinion on the Kaiser and the service AT&T provides?

[CDRacingZX6R]

Seems for the most part everyone is loving this phone. It's hardware is definatly impressive.

My main question is right now it comes down to the Sprint Mogul and the Kaiser. I have read the laundry list of problems that the mogul has had, so that is obvously scaring me a little bit. But I'm very much interested in the service of Sprint in terms of cost.

So just a few questions for a newbie if anyone would mind answering.

1) The data network for both companies is good. Which one is considered better and faster? No point in web browsing if it takes an hour (currently switching for T-mobile, so you can understand my pain).
2) Overall if you upgraded from the 8525, or 8125, was it worth it to you for the upgrade? Or do you think maybe you should have waited.
3) For those with AT&T unity plan, does that mean you can call, or get calls from anyone with AT&T or Cingular and not use up minutes? Cause if so that would be a pretty sweet deal considering so many people have AT&T at home where I live.

And lastly, does this device support a form of flash? I'm mainly concered with steaming sirius radio from my phone, so I was just wondering.

Thanks for anyone responding.