Thanks for all the feed back folks and big thank you to you JA.
Didn't realize that my 18-200mm would a decent performer for AP. Never really contemplated using it due to not being able to use my CLS. So thank you JA for that filter option. My knowledge is very limited with AP. It's why these forums are an awesome thing.
Queried a few camera stores before posting this thread on the Sigma 24/70 and was told that it would or be a winner of a decision to make a purchase and would out shine the 18-200 hands down. Wasn't overly convinced on the negativity of the 18-200. Sounds like they were only after a sale.
So looks like I'll save some $$ but in saying that it certainly would be nice to get my hands on canon 24/70 v2. Can't justify that price now though. My wife would shoot me lol. Perhaps just wait until I can save more $$ for a better quality lens or buy together with a full frame body.
I quite like the idea of a 18-35 though Hemi. But I'm assuming with JA's opinion which I'm agreeing with, that perhaps still stick with the 18-200.
Looks like if I do invest in glass why not go wider like a 10-22mm. Still a decent hit for the pocket for a EF-S glass though