At the time, they were good for what they were. They certainly learned a thing or two by the time HG/SS came around though. Compared to RSE, however, FRLG did lack a few things that could have made it better: lack of weather effect, no new Pokémon included during the main play-through, and very little graphic improvement are some that come to mind.
I never got to play the original Red or Blue versions ─ Ruby was the first Pokémon game I ever got ─ so I couldn't compare the original with the remakes. I do know that the remakes were very much like a carbon copy of the originals though. Not much was changed to make the game play feel somewhat new or refreshing other than what they added post-game. This is something they learned from when making HG/SS I thought.
Overall, like I said, they were good for what they were at the time. I certainly had my share of fun playing them.