Open up cabinets and storage area and compare the various brands on how well they are constructed and how accurately and cleanly the tradesmen assembled them. Look at the plumbing fixtures and door hardware between brands - Which ones are solid and have positive engagement? Since you have owned RV's in the past, you know what you do and don't like about your previous rigs - Do these TC's meet your expectations?
We went from an 11,000 lb bumper pull toy hauler to our 4000 lb TC with 7000 lb enclosed trailer. It can be done with a 3/4t truck, but expect to spend $2000 in tires and rims and $1000 in suspension upgrades in addition to the tie down and hitch costs. We were able to keep our existing truck instead of having to sell the entire setup and start over. If you have doubts about your truck, start with a DRW platform and you will have more options and less upgrade costs.
