The hotels you've mentioned in KL are all significantly better than the Sheraton in Penang, no doubt about it. From a tourist point of view, Georgetown is not the most alluring destination. There's Penang Hill, Batu Ferringhi, Fort Cornwallis and the ubiquitous Chinese shophouse architecture, and not much else. There are, however, plenty of dining and shopping options. Alternatively, you could stay at Ferringhi on the west shore of Penang. I would then choose the Shangri-la located there. The beach is nice, if not spectacular, but I admit I've been spoiled by those in Thailand. I guess it's all a matter of where your interests lie.

I've stayed there a number of times, and as A SW Platinum I've always been upgraded to a suite. They are very much nicer than any of the other rooms, believe me, but not nearly so posh as those at the Sheraton Imperial.