When I bought my 15 Ram I got the SB as it would be my DD and used to pull my TH.
I got the 3500 as I knew I would eventually get another TC.
Even though there are many SB TCs, The Ram only has a 6'4" bed which creates a pretty good overhang for any TC. The front of the bed also has a pretty good curve which puts the camper further back then what it looks like it should be.
I just bought an 09 Lance 815 with fiberglass sides, elec jacks fully loaded from a friend for a great price.
It mounts ok on the truck but has a 24" overhang. The Lance doesn't have the SB skirts so I would have to buy or I'm thinking of making some out of diamond plate material.
Hate to admit but the SB Ram looks disproportionate with the big crew cab and SB.
I also want to carry a dual sport M/C on a hitch rack and will have to use a 24" ext and I'm not sure if the stock 2 1/2" hitch will be enough for 400 lbs at 24" ext.
Good thing is a buddy wants my truck and there are some smoking deals on new 15s. $10k-14k off sticker.
I will save a few $$ by not having to get the SB skirts and won't have to upgrade the hitch. I'm sure the LB will ride better with a better CG and has 600 lbs more payload.
I also bought a Jeep which is now my DD so the truck will be used for the RVs and when I need a truck.
I'm looking at only $1k-3k to swap into a new LB so thats good. I have some extras on mine and would get a few less options on the new one. Will be a 3500 4x4 Aisin for sure.
Moral of the story is think hard about a SB if you want a TC.
13Jeep Wrangler
07 Ragen 21FB
12 Yamaha Super Tenere
14 Suzuki DR 650