I have tried a few of the three blades available. I have until recently always seem to end up back to the two blade props, so I think its very much a matter of preference. I have found that the Mezjlik 20x13 didn't have the performance that I was used to with the 2 blade, and the battery consumption was higher than with the 2 blade. The Falcon 20x12.5 was better regarding the battery consumption, but the speed was just a little too slow to be acceptable across a broad range of conditions.
I recently tried the Falcon 19.5x13 3B, and I think this one may be a winner. The battery consumption seems to be similar to my favourite 2 blade (Falcon 21.5x13), however I think the constant speed appearance of the flight is better and the natural braking of the prop is better. Vertical performance is still good as well.
All that said, its still a lot based on flying style and your model, so I think you have to experiment, which can cost a few bucks, but I would recommend the Falcon 19.5x13 3b as at least a good place to start from.
Chad