FI is NOT new, maybe on lawnmowers it is.
My experience comes from automotive, and having taken engines apart to examine for wear, FI engines exhibit far less wear on the [expensive] parts. 100k used to be the [rough] threshold for engine life/wear. Well maintained engines=more, less maintained engines=less, but if an engine had 100k on it, you'd take it apart to look at it.
FI engines cylinder/piston last much longer as the cylinder walls are not getting "washed" down with a solvent [fuel].
Besides the benefit of lower fuel consumption, engine wear is reduced dramatically.
The only thing that I'd worry about with FI is that they are programed to run [very] lean [hot], not a good thing for air cooled engines. So, a little reprogramming would help, otherwise, there is no "downside" to FI.