First, sounds like you had a good experience on the range. That is always fun. Also, the D2 is very good driver and easy to keep in the center so I don't know who gave you the impression you weren't ready for it. The FT-i is a high MOI driver and it isn't designed to be shorter or be a compromise driver at all. It is perhaps not as workable as the FT-5 or the D2 but it is just as long or close to it and it gives better distance on off center hits than those other drivers. All are great drivers including your TM Burner.
Some pro's will only hit a new driver maybe 4 times before deciding whether to pursue it or forget it. The right combo can make a huge difference without any swing change. It sounds like you found a head and shaft combination that really works for you and that is a great event for anyone. It doesn't mean the FT-i is a better driver, just that you may have found a combo that optimizes your swing. Keep experimenting and enjoy.
By the way, with those distance variables I would hazard that making consistent center contact with the driver is a bit of a problem for you right now. We all sometimes have that particular problem, especially when trying to hit the ball farther. On some drivers, a 1/2 inch miss can result in a 40 yard drop off. Again, the FT-i is specifically designed to minimize distance loss on off center hits. It may be a great club for your current swing.