druze, the key piece of advice is to make sure that TWC does NOT give you a SA3100 box. That box is old and does not have any DVI output. I've also heard it has inferior picture quality.
The other two boxes in TWC's circulation right now (the SA3250 and the Pace box) are both popular, and both have people who love them and hate them.
I have the SA3250, and like it better. It strikes me as a well-built box that's pretty reliable and has a good picture quality. When it was first released, the DVI port did not function, however, it has since been activated, so this is no longer a problem. Some people really dislike how the 4:3 pillars are a light gray color on it. I'm fine with this since my HDTV is a silver color, so it blends well with it. This, however, might be an issue for some people.
Other people prefer the Pace box, as it's more recent, and was DVI compatible right out of the gate. I believe it has some additional ports that the SA3250 does not, HOWEVER, it does NOT have an RF output jack, which has peeved off a lot of people who use it for Tivos or what-not. Another complaint with the Pace boxes is that they have a much higher rate of failure than the SAs. I used to work for TWC-Raleigh, (I finished my job there last week, which is why I had a lot of insider information, I didn't want to say so at the time though because I didn't want to risk my job on it.), and while I was there, we had a whole bunch of people return defective Pace HD boxes. Some of them were fried entirely, many of them just had their clock displays screw up. While I was there, I saw no SA3250s come back defective. The Pace boxes do have black 4:3 pillars, and are more adjustable with their picture output options, which many owners love.
It's really a personal decision between the two.. both boxes have pros and cons working for them, you just have to decide what aspects of the box are more important to you. Either the SA3250 or the Pace will serve you very well. Good luck with your purchase.