I like all modes (except TC), but I hate shitty maps. That said, Payload tends to take longer than the other modes, so we spend more time playing payload than other modes, even if we play an equal number of maps.
I like Arena, but the problem is the way it handles teams. Basically, it takes the maximum number of server slots and divides it by 3 to make 3 even-sized teams. So, on a 24 person server you've got 3 teams of 8. it always fills up the two playing teams before adding people to the bench team.
Team A and B fight while team C spectates. When one team loses the benched team gets swapped in. The way to get around that is to increase the maximum player count, but only during arena maps. On the old server we could do that no problem, but with the current hosting we pay for slots, so we'd need to pay for the extra slots and even then it'd still be limited to 10 players per team with 4 people sitting out on a full server.
The way the server is set up now, arena shouldn't come up in a vote if there are more than 12 people on the server unless someone nominates it. Not sure if it's working properly, since i don't pay that much attention and arena never wins votes anyway.