Deluge
Sometimes the speed limiter comes in very handy. Most the time I can set a torrent and forget it, so to speak. But other times I need to change the Speed Limiter settings for several torrents. Mind you that I keep a lot of torrents active so that I can support low-seeder torrents on public trackers and also to maintain my ratios on private trackers. ATM I have about 80 torrents seeding, and 5-7 leeching. I know that there is a lot of talk about managing seeds and queues to make this sort of usage a little easier / better to manage. But in the meantime the Speed Limiter has been a help. But it is also a pain...
When I really need to use the speed limiter most, I tend to have a lot of torrents that I would like to affect at once. Presently I cannot multi-select torrents in the main window and have the right-click settings apply Speed Limiter settings to all those selected torrents across the board. Right-clicking, checking, setting, and moving on through a list of 80-odd torrents is a real hassle. Of course it's better than no option, don't get me wrong. I am truly very pleased with Deluge overall. I am only picking knits because I love it so!