Lens dilemma

I've been using and loving the Canon 7D since early this year. The kit lens (28-135mm) has served me mostly well, and I've purchased the dirt cheap 50mm f/1.8.

About two weeks ago I purchased the Canon 16-35mm f/2.8L after some research and looking around. But I'm having second thoughts on whether or not it's the right focal range for me. It's a great lens, sharp and made very well. I'm able to return it for a refund (Amazon, just have to pay shipping) and have about 2 more weeks to make that decision.

I'm basically looking for a great all-round lens that's better in image quality over my 28-135mm. I like street photography since I live in San Francisco, so getting up close to things isn't always ideal. I've considered getting a better 50mm lens, the 1.2L, or a standard zoom like the 24-70mm 2.8L. I did briefly consider the 135mm f/2 but I fear it might be too zoomed in with the Canon 7D.

So any advice would be great!