I don't suppose there is a magic amount of time to research your next RV purchase. My wife and I spent 2 years searching for our first TT and enjoyed it for 12 years. We then spent 4 years researching FW to see different floor plans, weights, tow vehicle requirements, etc. We enjoyed going to RV shows and dealerships to crawl all over the different brands and playing with all the gadgets. The journey of finding your next RV is half the fun! You will soon narrow it down to the floor plans you like and the must haves and the nice to have gadgets. Then you narrow it down to a few manufactures. They all have their pros and cons. In the end you will make the best decision you can from all the research you have done and the budget you can afford. Taking the time to do the research will lessen the second guessing if you made the right choice or not. We bought our first FW after researching 4 years and have never regretting one minute of the journey or the choice we made.
