We switched our Dometic awning with the Carefree unit when our Dometic failed. The Carefree unit I much better built, and comes with a one piece cross bar vs the two piece of the Dometic (which is what failed on ours).
The mount to the top is the same, they both go down the channel mounted on the roof. You will have to change the lower brackets which involves drilling. Watch where you mount, because not all of the outside wall is supported. Look for the support "studs" to mount into.
The only issue I had with the conversion is that the Carefree unit was longer, and I had to get it shortened. By this time I was too far into it to turn back, so I brought it to an awning shop to have about a foot cut out of it. Looking into it, the dealer I ordered it through bought the wrong one, so be careful when ordering. The best way is to get on Carefree's website and get the exact one you want, then give the dealer an exact part number.
Overall, I'm happy I made the switch. The Dometic unit was so flimsy, I wasn't going to pay that much just to have it fail again within a couple of trips. Carefree units are more pricey, but you get what you pay for.