I don't use a 24mm, but I use a 28mm lens. It really depends what you want to do. I shoot mainly concerts and I use the 28mm mostly for the perspective I get with this focal length (in comparison with similar frames shot with other lenses, since I need to get closer). I also use it for full stage etc. where it is almost always good, but occasionally slightly too long... but, for what I mostly use it, a 24mm lens would definitely be too wide, so I prefer the 28mm.
If the type of photos you want to do will be good with a 24mm lens then I'd say it's definitely a good option. I could "live without" the 28mm/24mm but would rather not. If I had to I would just not take some of the photos I now do.
