Here's some rambling thoughts....

I have 2 Motorola SB5100's. They are now saving us money.

It's a bit of a gamble buying your own. There's not really going to be a speed difference between them, they all have to comply to the same standards.

If your cable company, in your area, is thinking of upgrading, your new modem will me SOL. If you bought it, you have to buy a new one or rent theirs. If it's theirs to begin with, they are responsible for taking care of your upgrade.

Average modem rental cost is $3-4/month. Average cable modem you can buy at BB or CC or Walmart is $50.

For that modem to be cost effective for you, you'll have to own it for between 16.66 - 12.5 months. So a year to a year and a half before the amount of modem rental payments starts to cancel out and favor you. The gamble part is big, are you planning on moving? Does the new place have cable? Can you use it there? What if a power surge hits and takes out the modem? You'll have to wait, at best, for warrenty repair or buy a new one which moves the time frame back a bit. If anything happens to the modem, you are responsible for it.

For me, I took the gamble and bought 2. One for me and one for maw. This was well over 3 years ago and they are working fine and saving us money now.