I own 2 burbs and a jungle carpet and a coastal carpet plus I have dealt with many others of both species over my time.
I guess you could say they are similar like you have mentioned but at the same time not. Carpets don't have a lot of girth To them but do have a lot more then Brbs when adult. And are usually a little longer too.
Brbs will tend to do a little better in a bit cooler temps then carpets. Most sheets say 85 for Brbs but they actual tend to do better in a little cooler then that. My hot spot is only 82 for them but they spend most of their time on the cool side of the tank.
My Brbs will spend almost all their time in hides. My jungle will spend time in hides but also a lot of time perched. My jungle tends to be out way more then any of my other species of snakes.
Brbs also need more humidity then jungles do and aren't as tolerant to not getting that humidity as jungles are.
Both are quite aggressive eaters. Jungles a little more so then Brbs.
When being handled both are a very active snake. Both can be quite quick with their movements too. Both more active then common boas. In the tank they are both snakes so you most likely don't get a ton of action out of them but both species are still active in their tanks. Jungles I would say are more active then Brbs in their tanks from my experience.
From what you want I think you would probably enjoy both but might like Jungles a little more.
That's the kind of comparison we need here!
Nice rundown without any bias since you own both.
That post probably helped many more people than any of us know.