All of the FF games can be completed around 40 hours with everything minus excessive grinding done. That's how I did them all through X-2. I can't imagine how you spent 80 hours, because I'm not sure it took me that long even on my excessive grinding playthrough. I am also guessing you left the system on without pause.
There are definitely games that take that long and longer though. I think my final time on Disgaea 1 was 200 hours before I finally put it down. But then, that series is entirely
about the grind.
As for how remakes of the PS1 games might look? It can probably be determined by looking at Final Fantasy IV DS. Improved graphics and voice acting. Some minor additions (new items, semi-customizable summon). A major new game system that still fits the overall game quite well. And I think it had a new superboss? (Kind of hard to remember which features were in Advance and which were DS.) Its a bit of a toss-up at to whether Advance or DS is the definitive version (depending on what you thought of the new dungeons in Advance), but the DS edition is certainly worthy of serious consideration. (Haven't played the FFIV trilogy on Wii.)
Most of the X-2 hate comes from people who cringe at the thought of playing Yuna's Magical Hotpants Adventure. Which is at least mildly understandable. And the core story in the game ranges from poorly handled to utter garbage. The game certainly has some mis-steps here and there. Like the entire chapter you get to spend watching web-cams.
But the side stories are kind of interesting, the class system is pretty good, and the battle system is probably one of the best. Some of the mini-games are also neat, but that's a decidedly more mixed bag. What has me interested is all the additions that were made to the international version. Its somewhere between a DLC and an expansion pack.
I'm holding out for an insane hope that it will come to the Xbox, since that's my preferred system, but I will definitely be picking it up.