does this make sense?

I'm currently interested in buying a sigma 30 or canon 28. I figured I might ask you guys first if that make any sense or should i look into other lens? just bought a 7D which haven't arrived. currently my lenses are canon 10-22 f/3.5-4.5 and a tamron 28-75 2.8. i'm trying to build something mostly for low light and street but would be useful when i go travel and trekking/hiking. sorry if it doesn't make any sense.

Um, a little confused... why wouldn't it make sense? If those focal lengths work for you, then those primes are excellent for low light work.

Set your zoom to 30mm and leave it there for awhile, does it work for you? If so, then it's a good choice.

I've owned both lenses and personally, I'd pick the Sigma 30 over the Canon, especially since you have a 7D which has micro-adjust.

i read some people here received not so good copies of the sigma which worries me.

The whole Sigma issues are blown way out of proportion. I've used many Sigma primes and I've never had to send one in. The Sigma 30mm also has a better track record than some of the others. However, it's really up to you. You've already started a thread and some people have told you it's been fine...not sure what you're really looking for. There is also a poll linked to your thread. If you're worried about it and if it'll help you sleep at night, just get the Canon.

try them both out in store. it was a really tough decision for me. i liked the performance of t he canon better, but there's something special about the IQ of the sigma.

i think i'll take the sigma based on the the replies. many thanks
TTHX, i can try it in store but then again i'm planning to buy online.