Been looking into getting a new walkaround lens for a trip to LA. Id been working with a Sigma 18-200 but its just not sharp enough for me. I was considering the Canon 24-105 F4 but wanted to consider alternative mid range zooms due to the distortion at 24mm I keep reading about. Has anyone checked out the Sigma 24-70, theres one on ebay for like $350. I was thinking of going Canon 24-70 2.8 but at around $700 that may be a little much since I only use this range on vacation. Any input would be awesome, or other lens recommendations. Trying to stay around 500


