I'd like to get either an E73 or N900 to occasionally use with a pre-paid (Tmobile USA) account for tethering.

Does anybody have any experience tethering either device with a pre-paid account? Which would you recommend?

Do they both do 3.5G speeds? Is the connection stable? Is one better than the other for proxy/VPN software (I suspect the N900)?

The E73 probably has better battery life, but he N900 has a good web browser.

I have an employer supplied AT&T voice account that I use with an Nokia E72.

My experience with the n900 has been good with tethering via usb or using joikuspot as a hub.

Though, I'd prefer to tether with usb cable due to the battery life not being the best when using joikuspot (1-2 hours).

Stability and speed are a function of signal strength. Where I live, my 3G signal is very weak. So I have to resort to using Joikuspot by putting it on the window or outside the house and receive the internet wirelessly. Otherwise, when I have been on the move, if there is full bar on 3G, it works flawlessly with a 1.5MB connection at best.

The battery life on my wife's n8 leaves the n900 for dead when it comes to the use of joikuspot. We've both shared the connection for 5+ hours and the battery bar on the n8 dropped one bar in that time. I suspect this would be similar in respect to the E73.

The above experience is an Australian provider called Optus.

Some more info here:
http://talk.maemo.org/showthread.php?t=30732