A lot of good advice here. My input would be to go very slow with your upgrade process. If you are or want to be serious about your HiFi and get the most for the least amount of money you should start with your room and isolation/decoupling of your components. Not as exciting as buying new speakers but probably more important. You can go down the rabbit hole of studying & learning how to make your own room acoustic pieces instead of spending big money on manufactured stuff. You can look into DSP if hanging things around the room isn't practical for you..but treating your room will get you the results you are looking for.
I say go slow because it seems you haven't dialed into the exact sound you want or how to get there. You have quality gear already. I have not heard your Legend speakers but I've owned the Reserve R200 & R700.. actually still have a pair of the R700's. Contrary to the negative bias many have toward Polk their newer models are quite capable of good music when paired with quality components. I understand reasons for wanting to upgrade from them but they are good enough to keep using while you work on your room.
When you are ready to try different speakers look at ones that will pair well with lots of other gear..because you will probably want to switch that up at some point as well. Speakers with a higher sensitivity and easy load for any amp. You never know, you may get interested in tubes or Class A at some point. Maybe look at used. Be patient for prices and brands that you could resell easily without taking a big financial loss. Good luck.