AFAIK they all work the same regardless of which service you are on. I would just find one that matches your requirements (need 300N? A-C? gigabit? WRT/Tomato compatibility?) and doesn't have a bunch of bad reviews.
I also have a Motorola 6141, and so far so good (since December). I got it because Time Warner started charging $4/mo for modem lease, and getting the Turbo service "required" a Motorola 6850 that has a built-in WiFi router, incurring an extra $11/mo "home WiFi" service fee. Buying the 6141 and using a pre-existing WiFi router saved me $15/mo, thus paying for itself by next month.