If you want to judge the speakers, try near field listening. Get the speakers away from walls, maybe a 3ft/1m triangle. See what they sound like in that situation. In other words, try to take as much of the room out of the equation as possible. Because...
...that is a problematic space!
I am not sure how floor standing speakers would change things in this space. A bit higher tweeter position would be likely, but given the high ceiling that doesn't seem like it would alter things in a big way (all things being equal).
I will suggest something to try. Flip your speakers over, tweeter on the bottom. Angle them SLIGHTLY up. See how that sounds.
The idea is to send more reflections up to that second level, which hopefully can eat some sound for you. It might help, it might not.
Personally, in that space, I would try shifting the speakers over to the right, and angling the seating area a bit. If you get the left speaker out of the corner a bit, that might help. If you do try this, getting the balance of sound from each speaker, given different sidewall angles, will take a bit of care. At a guess, you will want the left speaker closer to the wall than the right. How much? Experiment.
When you do, whatever is behind that seating area matters. If you can send more reflections away from the main area into other parts of the space (kitchen, hallway for example) that will help.
Asymmetric set up can help with asymmetric rooms, but it's a pain to get right, and always involves compromise. But defintitely keep symmetry for the direct sound-listening position when you try options.
I would try those options first, since they are free and easy to try. Then I would see what I could do with some PEQ settings. Depending on the results, I might then try some room treatment (curtains, something on the wall between the windows, that kind of thing). Then I would decide if new gear would be in order.
