My race bike is a D6 as well and while its the only TT bike ive owned, i really do like it a lot! My roadie is an Altimirra that i like but am thinking about swapping for an SST since the SST is a bit stiffer and has a bit more agressive fit. The only issues ive had with my Fuji’s have been a couple loose spokes, NBD. And when i bought the D6 there was an issue where Fuji wasnt shipping bikes with the setscrews in the dropouts. I asked the shop i got it from if they were there and they assured me they were, me being a dumbass i took their word for it and come to find out after 2 rides and much wheel rub the setscrews were in fact not there! I emailed fuji and they 2 day aired me the setscrews.
FYI, if you decide to purchase a bike from performance, they have a 1 year love it guarantee! ride it for 6 months and if you dont like it and want to switch to something else they sell you can do that.