It is a challenge to figure out what you want w/o experience. One approach is to get a reasonable used coach and learn with a plan to change down the road.
With our 5+ months on the road I appreciate my 2 5' pass through storage slides and each extends 5' on either side. I do lose 3' of storage on either side with the tag. But 99% of the couples are satisfied with whatever she likes which has nothing to do with storage as that's his domain.
I do miss not being able to go to Ft Bragg, CA. There are good county roads to get us to Bodega Bay and we'll be there next month. I wouldn't take a rig on the highway 1 Big Sur road and it is also prohibited over 40'. I wouldn't have a problem with Tioga Pass Rd but any 8% grade needs to be taken seriously. I do have reservations about the tunnels and roads on the western exits.
Regardless of what anyone suggests the longer the rig the more restrictions you'll have with CGs. Yes sometimes you can get into a shorter listed site but not always. There are apps that will display only 50A 60' pull through sites - it just depends upon your camping preferences.
