242 Panels behind speakers

[Superfrg]

I have a few cable&tube upgrades on the way, but now im FINALLY dipping into the acoustic treatment path as well.

Its taken a while to convice my other half to move into this area, as my listening room is also our main living room.
However due to pressure, favours, and time, its now possible.

I've read alot and bought some starting gear from GIK.

2 x soffit bass traps to front corners, (bottom to ceiling)
2 x freestanding bass traps rear corners (cant fit anything else there)
2 x 244 bass traps 60x120 cm(putting one behind listning position, as its near wall, one in spare)
4 x 242 panels 30x120 cm

So i've bought the above due to room layout mostly, and I'll use the 242 panels for first reflections on either side untill I get some aku-art of some sort in the future.

Now the question is what experience you Guys have with mounting 242 panels behind the speakers, covering first reflections to the main listening position?
I have two 242 panels 30 x 120 cm to put there.
From what i've learned through searching the web, its a bag of mixed results.
Some liked them, some did'nt.

Whats your experience, and what height would you put them in?
Obviously covering the ear level, but from bottom or raised a bit or?

Speakers are Sopra no 2 and they do not have rear bass ports.