[nobo]

Thanks for posting Joel!

+1 on what Chris said. Acoustic treatment will make a big difference/improvement (I would say, "the" biggest improvement; all the more so as on a bang per buck basis). 45 or 60 kg/m3 rockwool - 4" or, better, 6" thick - wrapped in a a breathable fabric is cheap and will do the trick. You can use these as gobos and/or position around the room. In the tricorners will make the biggest difference to the troublesome low and low-mid end. If you're putting them elsewhere on the walls/ceilings, space them away from the wall by their thickness.

You can use ReadyTraps/ReadyBags for a more aesthetically pleasing version. They also have a free acoustic design service to help with positioning.

My Kostal MD arrives in around 2 weeks time - do pop round with the Greenfield and maybe your mics and you can try them in a treated space in my studio: it's unusually dry for acoustic guitar recording, but then you're free to add reverb to taste.

Looking forward to catching up in person!

Dan