Unfortunately, many dealers will sell you anything. I'm not saying they are misleading, but what they think is a good setup is sometimes marginal.
If you are leaning toward a DRW, I'd just do it. I had a SRW for 8 years with my current camper, and eventually added the mods mentioned here including 19.5s. My F450 obviously hauls it better. There are a few of us here that went from SRW 19.5s to DRW. The SRWs were ok, but since I can get by with a DRW, I made the switch.
If you take your time doing the deal/trade, the current truck should bring a good value. On the other hand, if you plan to rarely use the TC, just leave it as is.
