Had a game against cosmoe and revealer yesterday evening (we were 'premade' meaning my team had voice) and the core of the game was mainly to repeat flag lock on ennemy portals. In the end we win, but I felt like I did not have as much fun as I could expect.
replay : http://www.megaupload.com/?d=G6B8VL8J
Theres definitly something to change here, or to improve, this is quite annoying that a single liitle error (having a portal capped which can happen if noone pays attention in your team) leads to that kind of gameplay. Maybe it is just the map design on cataract.
Maybe change the rules a bit so that the flag can be switched to neutral when you are on it even if an ennemy is present too (not on all flags, only on your team flags - i.e. those you controle at the start of the game).
Or maybe change the lock duration : 60s on team flag, 45s on neutral flags and 30s on ennemy flags.