I still haven't officially voted as I'm yet to see the Starfish to make a judgement .... however last night I had my first personal view of M13 and while I was quite taken by it's flailing "arms" as such I then swung my scope immediately to Omega Cent.
No comparison, none at all!
Mind you the viewing were just a tad biased - M13 was very low just a bit above the northern horizon, while Omega Cent was riding very high and only a little past the meridian
but even if the relative viewing altitudes were reversed Omega Cent would still stand out like canine spheroids!