When I selected my first kayak, i went through the process of choosing kayak rather methodically. Paddle selections was handled in a much more simple way. During the kayaking course me and my wife attended when we started paddling, we got to try out different paddles, in the same way as we got to change and choose kayak. That is, we normallt changed before every new course part. I had very little knoweldge of paddles, and very little interest in how a good paddle should be.
So I tested many paddles in the same way I tested many kayaks, but for me, the paddle testing did not include any selection made by myself, I asked and got different paddles. They all worked well. There were neither greenland paddles nor wing paddles on the course, so basically we were getting to test different euro paddles only.
The paddles were of different sizes, with shaft of different width and length and also some with angled grips. Some of the paddles had zero degree angle between the paddle blades, and others had higher angles, up to 60 degrees. All of the paddles I got to test worked well. The teacher saw to it that I did not get any with thin shafts, but that I believe was the only limitiation on the paddle choices he used.
To compare kayak paddles, you need to know what you want from the kayak paddle. This is described in comparing kayak paddles.
My thought on this is that unlike a kayak, if you are choosing among the standard kayak paddles, you are fairly well of almost independent of choice. Yet, there are differences, and the pluses and minuses with those differences take more testing to find than when comparing sea kayaks, but also for kayak paddles, or maybe even more for them, the more skilled you are at paddling kayak, the easier it becomes to notice the differences. Also, the better you become at paddling, the more important the differences become. Something you might evaluate as a positive difference in a short term test (larger blade, better grip, or wing paddle blade, better grip) might after a couple of hours of paddling, or in another situation, for example more wind and waves, turn out to have a drawback that is not acceptable (to much strain on the muscles, or too weak low bracing).
In fact, just like when choosing kayak, the end choice is about feeling comfortable, especially feeling comfortable in the long run. Since I made a choice on my first paddle that I currently consider as an overall drawback compared to my new Werner Athena kayak paddle, I now travel with a spare paddle. If I get more muscles and can handle longer paddling tours better, I might turn back to the first paddle I bought. This is yet again indicating that the choice is about pluses and minuses, where pluses and minuses are reevaluated depending on circumstances. The final choice is made to make the positive sides weigh higher than the negative sides. There is not main "it is better in all circumstances" choices.