I grew up on FFIII man and I played through that game so many times. If there was to be a next gen. FF that is able to deliver what that game did for it's time in next gen. graphics, you'll have the best FF to date.
the polyfilla way look strong in the weakness of the gaps
They fixed only the battle system problems. Not everything like you claim. And as much as you'd like to say it's underrated, I'd argue the opposite: it failed miserably in the story department. I don't blame it, as the original did a great job giving this one a failure to start with.
Overall, the game isn't better than other games, and it's not deep enough to have a superb combat system. It's quite shallow, much more shallow than the original was.
I would rate it higher than XIII, but only because the gameplay offered more "entertainment" than watching movies and mashing x or inputting annoying simple commands majority of the time. It was less of a grindfest than the original, but still not good enough to get the same experience I got from FFX and FFXII and X-2. X and X-2 offered the best battle systems, with XII being my personal favorite as I loved running around solo'ing monsters in like 1 vs 20 type of odds which lagged horribly though.
I hope you pick up X and enjoy that the way it was meant to be played: no sphere grid, summons, and so forth. Then you'll experience the true composure needed to play RPGs. You really gotta plan your way through that mode. Fun, but very challenging.
Vadimony, if you like the strategizing required for X/X-2, you'd probably enjoy FFXIII challenges as well. Obviously, you don't need a high level of strategy just to get through the game (which I'd argue is also true for X, incidentally), but that changes in a hurry when you start pushing for optimal battle times or taking on various fights at lower development than intended.