Hi guys,i was wondering on what kind of walk about lense to get.Since i'd be taking most of my pics with such a lense,i would like to invest in a good one and the above mentioned seems like a good choice.So any opinions of anything better or just go ahead and get that? I'm using 30D and am really starting to see the horrible flaws of the kit lense. Recently took a group photo of about 20 people and the corners were crazy soft....