Lens advice?

[CRAZY_JAY]

I am looking to get another lens and would like to know if anybody has experience with ones I am comparing. I have read a few reviews on both but another opinion always helps.

The Canon 24mm f/2.8
http://www.the-digital-picture.com/Reviews/Canon-EF-24mm-f-2.8-Lens-Review.aspx
Sigma 30mm f/1.4
http://www.the-digital-picture.com/Reviews/Sigma-30mm-f-1.4-EX-DC-HSM-Lens-Review.aspx

It will be used 80% percent of the time taking pictures at concerts, parties, and bars. It will need to work well in low light and focus quickly in low light. I will be using it with a Canon XTi and at times with the 430EX flash.

If you have a better suggestion I am open to other recommendations.

[speedminded]

The f/1.4 is obviously going to be better in low light situations...but locked into 24 or 30mm might not be the best idea. Personally i'd look into a zoom lens.

[CRAZY_JAY]

The reason why I am looking at a prime lens is because they generally work extremely well. For my usage with this lens if I need a tighter shot I can usually just walk closer. The concert venues are small so zoom is not important. The size of a prime lens is a huge plus, they are smaller and lighter weight than a zoom lens.