For a full-time bed, you're really looking at a 24 ft. The B+ is really a C just without the overcab.
Since you won't be using the overcab for sleeping, it comes down to whether you want it for storage or to house an entertainment center (or you might bring along a grandchild, etc., who could sleep in it).
Lots of threads about the beds - especially walk-around bed recommendations.
As you currently have a B and love it, seriously consider whether you really need a slide. You may find it more "effort" than you want since you're used to simplicity.