knives that open with the wave are a bit of a hit and miss in my opinion. they require some practice, appropriate pants pockets(material of the pants and the shape of the pocket play a part in whether you can even use the knife with certain pants or not), and even then you'll get the odd occasion where you miss the opening.
Cold Steel's thumb plate works well too, but again is dependent on the pants material. I've had it snag and get caught up in some thinner pants i wear during summer.
I'm not a big fan of the Spyderco waved delica/endura, as I personally think the wave is located too forward from the pivot and it's too big. I've had both get caught in the pocket numerous times as the wave digs into the pocket material before reaching the pocket lip. they do both work well in reverse draw however.
I personally think the Emerson CQC-10 is the best waved knife available, as sometimes the Emerson thumb disc will cause a missed opening(usually on tighter pants, the disc spreads the pocket edge just enough so the wave can slide off without catching fully), and the thumb hole eliminates that.
I currently carry a Gentleman Jim though and it has been great, one of my favorite knives ever. couple things to keep in mind about waved knives: 1. they're not really practical for when you're sitting down or laying on your back 2. get used to repairing pants pockets