It depends on where you are, if you're in a area that does not have 3g, than you won't get it, vice versa.

Also, I'm currently using my good old $5.99 T-Zone plan and I'm getting 3.5g on my N900.

Now, here's a quick first impress of my phone(more like a impression I came up with after playing with it for over 8 hours):

I've used the device for a good 7-8 hours before the battery completely dies out on me. A good 4 hours of Wifi, where I am browsing the net, installing apps, and downloading stuff. Then the rest is on my HSPA+ constantly streaming music, while browsing the net. I did get a good half an hour of talk time in it. Seeing how I use my device, looks like I might actually need to get an extra battery just incase.

I do have to say that T-Mobile's HSPA+ network, or 3.5g is quite fast. The speed is actually on par with my wifi connection(my ISP is at 15mbps), it's just slightly, I mean literally slightly, slower than my wifi.

One thing I have to say, not having portrait mode was a little bit confusing to me. There was a few moment that I held my N900 at portrait and start shaking it, thinking, why isn't it going to portrait? Then I realize, oh yea, there's no portrait mode. Don't get me wrong, not having portrait is not really a con. It just needs some time to get use to.

After carefully examining the pictures I took with my N900 on my computer, I officially proclaim that the image capturing quality is mediocre. I can even say it's worst than my Samsung i900. I do hope they can improve the quality on their next firmware release.