Definitely worth a try. But it'd be a mistake to try them on one ride and give up on them. You have to get used to them to really appreciate them. Here's my experience:
First ride - First 5 minutes when getting on these rings felt really strange. Like something in the drive train is slipping. It's un-nerving to say the least and did make me wonder like this was a good purchase. After about 15 minutes that odd feeling has all but gone. They don't feel so strange anymore. That said, something doesn't feel quite right - I don't feel my normal powerful, smooth self on the bike for the duration of that ride. Just like when you get on a new bike I suppose and the position is slightly different, you feel like you can't efficiently output power.
Second ride - I didn't feel like the rings were an odd shape anymore. They feel just like pedaling any chainring in fact - and I'm starting to get properly used to them in that I feel a bit smoother on them and I 'forget' that they're there.
Third ride - Really liking them now, they do change your pedaling style but it doesn't feel detrimental to your ride. In fact it feels better - especially up climbs. Let me try and articulate it: You know riding hard on the flat is different from riding hard up a hill for a given intensity? Riding hard up a hill, you generally have a less smooth pedal stroke because a larger percentage of the bike's speed is sapped during the dead spot on a climb; you then have to accelerate the bike again in the power phase and so on. This gives a lumpy pedaling style which puts a lot of strain on the muscles and I reckon it's why many people don't like climbing hills - it's demoralising and difficult. What the Osymetrics do for me is make the hill as if it was 3-4% less steep. As in, it doesn't make it any easier, but it simulates a smoother pedaling style that you'd expect on a hill that wasn't so steep. Sorry if I've lost you by this poing.
Anyway - My Fourth ride. I was absolutely loving them and don't think I could ever go back to round rings ever again. I don't believe they've made me any faster outright, but I do believe my pedaling style has much improved in that I pedal much 'rounder' now. I focus more on pulling up my legs now so I feel as if my downstroke and upstroke are very equal and thus my pedaling more efficient.
I'm just rambling now but I think yes, they are worth it - but you have to give them a chance. Don't can them after the first ride because they don't feel quite right. It may take more time or perhaps less time for you to get used to them but make sure you try them properly before deciding if they're for you or not.
The improved pedaling style that you might benefit from could increase performance, sure, but the actual outright power gain I am greatly skeptical of. I have no way of proving it wrong, but it doesn't matter to me anyway as long as they don't actively hamper my performance.