I haven't played any other version of this, but a lot of the popular criticism of this seems to be that it's still pretty clear that this is an old game, mostly being a graphical update. To an extent, it does definitely feel like that though, shop system is relatively slow for instance. I don't really find that a bad thing, the original version hasn't had an official English release, so I think staying close to that is good. Besides, I don't think "feels like a SNES game" is ever really a problem.

Applying to both the OCU and UCS scenarios, you and enemies both miss a lot. Adds to tension but also makes things feel pretty luck based. There's also a lot of weapons and parts, but not actually that much build variety, generally just coming down to melee/short range/long range and maybe what legs are best for this exact mission. Also it would be nice if all that variety let us choose aesthetic equipment slots but that's a pretty minor complaint.

The UCS scenario was added in the PS1 version. Comparing that to the OCU definitely makes the OCU scenario feel aged though. The UCS feels much better. Levels are smaller but more interesting, there's less characters to use but that means less grinding and less characters who just feel like they're there. The story also feels more in depth, the OCU felt rather basic. I think this is a nice sort of aging, you can really see the series evolving that way.

If you're fine with a game that really feels like it was made in an older era with most of the updates being visual, you'll enjoy it.