Yes, you can switch from Tomato to DD-WRT. Just upload DD-WRT through the Tomato firmware uploader. I've done it on my WRT54GL. A few WRT models have customized mini DD-WRT images to start with as an initial flash, so check out your specific model first.

I bought 2 different models of Asus routers that were b/g. They worked great with DD-WRT for almost exactly 2 years, then they died a week apart from each other. Bricks. I replaced them with a WRT54GL. My backup for it is a WRT350N that someone gave me. That's right, the ol' 54GL is more dependable than the fancier 350N.

I'd consider Asus again, but only if I could convince myself to buy 2 so I could have a standby for when the first died.

Just consider this... do you really need the N spectrum? I don't personally do a lot of file transfers between computers on my network where speed is a consideration serious. If I was to saturate the whole allowance of G trying to hit the Internet, that's still more than what my outgoing cable internet service provides with Time Warner.

Moreover, to get full N, you have to broadcast 2.4 and 5 spectrums, and only one of the two goes far enough to get out of a room and through walls, so you effectively have G speeds in most N implementations anyway. Read about it... lots of people turn N off and go back to G, even when they have access to the fancier feature.

You can't leave out the fact that Google has advertising, analytics, feed proxying, and blog hosting everywhere - not just on *.google.com. Even if you don't click on ads, they can still profile your traffic patterns and sell their research findings.