Ok, so I took the plunge and purchased a 30d after using a P&S for a year. Its coming this week along with a 50mm 1.8. I know im going to get my hands on a 70-2000f4 hopefully sooner than later for moto-x that I shoot, so that leads me to the question everyone asks..... I wasnt able to do landscapes and architecture with my S3IS very well, but im very interested in trying, so im trying to debate getting the sigma 24-70, and then have a tokina 12-24 dedicated to trying that out? Or are there other good fillers for the range im missing? Ive been searching here, and it seems like the 12-24 is praised, and the 24-70 is very hit or miss which kinda bothers me. But im very interested in having a constant f# through out the range, as not having that was one of my pet peeves of the S3IS in the first place. Any advice would be great! Thanks!