I too get tired of seeing the same 10-20 champs 100 times more than I should during these modes. URF is the worst, though, due to it's extreme mechanics changing format.
Bans usually go as follows too: your team bans three, one of which is a useless ban. The other team bans three, two of which are useless. Now you have four ban champs out of, what, 20 or so champs. Ten people on two teams, you do the math. You're always going to have tons of the same champs and it makes URF boring as hell.
I have said for some time now that a "rotating ban" should go into effect. Next time we get URF for our special game mode, it should AUTO BAN the top FIFTEEN champs played LAST time URF was available. Then you STILL get the six bans between two teams on top of that for a total of (21) bans. Fifteen of which are guaranteed to be good bans.
To counter the problem of people who don't have many champs, the champs that are free to play during URF should 'NEVER' be on the ban list. You could also allow people who's champ pool is small to select from both this and last circulation of "free champs".
In short, these modes (especially URF) will never be balanced, but there are champs that .. balanced or not .. would be great fun to play. Just, not fun if you're HORRIBLY losing to no less than four of the top champs for the mode. There needs to be a method of "limitation" to hold back the "zombie generation" from just choosing the most overwhelmingly overpowered champions every single match. IT'S BORING KIDS!