I think FTG is better than Ameno cause Minato was able to transport a TBB to the sea in a split second and be back on the battlefield before the explosion hit whereas Sasuke Ameno is just object swapping an it's not like he can do it on a constant like a DBZ character can, it has it's moment where it needs to chill before the next jump.(Or that's what it seems like because he's only used Ameno to avoid one attack not several attacks simultaneously where he'd need to swap at very fast rates/paste)
Ameno is a nice tech but I think FTG is superior. Slightly superior but still superior none the less.