@rooze Having owned both ribbon planar and electrostatic speakers I can say they share a very similar sound. One may not be better than the other. It depends on the model of the speaker. Acoustat speakers can be very reliable, but you need to start with a good pair that have been well taken care of. I have seen a few where the glue is deteriorating and as a result you will get some buzzing and other issues. I owned the Acoustat Model 2 which is half the height and double the width of the 1+1. The panels are also angled within the frame. I would say that with Acoustat speakers, the biggest design issue is the transformer interface. You can say this about many other ESL speakers as well, but for me this was a big issue with the Model 2. Now, when I removed the interface and added the Acoustat direct driver servo amps this was a huge improvement. They were just as enjoyable as my Quad ESL with the servo amps.
I have never owned Apogee, but always wanted to. From other owner experiences they do seem to have more issues and of course depending on the model, you may need to lock in to a certain type of amplification. If I were to get a set of Apogee I would probably just make the investment to get one of the pairs that is more amp friendly and have True Sound Works restore them. However, I have owned Analysis Audio ribbon planars and they are very similar in design to Apogee and much easier to drive. I owned two different pairs and found them to be very enjoyable. New they can be pretty pricey, but if you can locate a used pair you’ll find some great deals on them.
I don’t want to dissuade you from the 1+1, they can usually be had a great prices and they are a true line array. If you get a good pair with the right amplification or better yet find the servo amps you will find them to be very enjoyable speakers.

