What I like about our cone skimmer is that it is REALLY simple to dial-in and it does skim well.
To be honest, I'm too lazy to A-B it with a non-cone skimmer (swap it out and test it on the same system), nor do I have a "non-cone" of the same rating. However, I CAN say I like it better than any skimmer I've used thus far (it bumped the RC-180 off the top of my list).