I believe the roman faction to be overall very good. Personally I like the Brutii (Green romans) as they have Velite Gladitors, which are goo against Chariots and Elephants, while the other two roman factions have Gladiators that are just powerful Infantry (and you'll never use). All roman factions (army wise) are the same except for the Gladiators. And I believe the Brutii to be the best as they can specialize against certian units, unlike the rarely used Julii and Scipii gladiators. In campagin mode though, they have many differences as to where they start and their main enemies.

The only problem I see with the Romans is their lack of Spearmen, and more percisely their lack of Phalanxs. Which I believe to be a very important part of my strategies. Most factions have Phalanxs except for some Barbarian tribes, but they do not need a more defensive formation, as they can just rush in.

Overall the Roman factions are great, and their campagin is alright too. If you're playing multiplayer and like to have a well rounded army I suggest you go for the Selecids. But if you're new and playing campagin, stay far away from the selecids, their campagin is brutally hard.