FBTR was always 'ok' but it was never a map that had much going on. Usually lots of camping or the odd push to central forest. The extremely open flanks meant that there was never many options for teams to try to push around to be aggressive. The defensive positions around the flags were also made more difficult by the approach positions having very poor cover against cavalry.
Personally from the list I would deselect Ruins. It's a camp fest, one flag doesn't work properly (despite multiple times of me thinking I had fixed it), the hills are obscene and rangers get to sit in comfortable little forts with huge amounts of visibility.
The whole nostalgia for original maps thing keeps coming up in tournaments, pretty much all of the original ones were never designed with competitive play in mind and have huge gaping flaws. The only unmodified original map which I think still almost makes the cut is FBTR, but even then you have places on it with ridiculous cliffs, no clear map borders and in general it doesn't have enough tactical openings to make it interesting.
Of the others:
Khergit Settlement
I enjoyed playing this in some training matches, I fear a lot of people will complain about it because of the amount of open ground however. The large amounts of open space might also make the vaegirs extremely strong on this as I don't believe there is much cover to give other factions breathing room.
Reveran Village
Still good, lots of different play styles work on this, the only issues I have are the deep water and poorly marked map borders, but we have lived with them ok up to now so I guess it's fine to continue.
Castellum
Pretty solid, it has a lot of different approaches and the tower often makes for an important early objective. The main criticism I would level at it is how open the spawns are, but that is more of an issue for public play than competitive. I have seen a lot of different builds work here as well, similar to reveran.
Frosthaven
I made it so I am naturally biased, but I tried to copy the style of reveran village as much as possible as I think that's one of the most successful and popular open maps. It hasn't been through any large revisions or changes yet so I hope it plays well.
Personally from the list I would deselect Ruins. It's a camp fest, one flag doesn't work properly (despite multiple times of me thinking I had fixed it), the hills are obscene and rangers get to sit in comfortable little forts with huge amounts of visibility.
The whole nostalgia for original maps thing keeps coming up in tournaments, pretty much all of the original ones were never designed with competitive play in mind and have huge gaping flaws. The only unmodified original map which I think still almost makes the cut is FBTR, but even then you have places on it with ridiculous cliffs, no clear map borders and in general it doesn't have enough tactical openings to make it interesting.
Of the others:
Khergit Settlement
I enjoyed playing this in some training matches, I fear a lot of people will complain about it because of the amount of open ground however. The large amounts of open space might also make the vaegirs extremely strong on this as I don't believe there is much cover to give other factions breathing room.
Reveran Village
Still good, lots of different play styles work on this, the only issues I have are the deep water and poorly marked map borders, but we have lived with them ok up to now so I guess it's fine to continue.
Castellum
Pretty solid, it has a lot of different approaches and the tower often makes for an important early objective. The main criticism I would level at it is how open the spawns are, but that is more of an issue for public play than competitive. I have seen a lot of different builds work here as well, similar to reveran.
Frosthaven
I made it so I am naturally biased, but I tried to copy the style of reveran village as much as possible as I think that's one of the most successful and popular open maps. It hasn't been through any large revisions or changes yet so I hope it plays well.