The configuration of the Manley Langevin Stereo ELOP is extremely easy to understand and follow. Each channel only has a few parameters to work with, including knobs for gain and reduction and a variety of switches. After a quick glance those of us who are familiar with compressors will be able to understand everything going on, and even those without much experience should be able to get the hang of everything rather quickly. I don't think a manual is necessary, but I haven't seen it for this unit so I can't say how well put together it is or not.
The sound quality of the Manley Langevin Stereo ELOP is pretty great overall. It has quite a realistic tone and is great in a variety of different situations. My favorite thing to compress with this is drums, but it will also be outstanding with use on vocals, guitars, and just about anything else you use in tandem with it. The unit is easy enough to use that I find it easy to manipulate the unit to get a variety of different tones, which is a big advantage with an easy interface like this one. I don't have extensive use with the ELOP, but for the times that I've used it I've generally been very impressed with the sounds that I am getting.
If you're looking for a stereo compressor that has a top notch tone, the Manley Langevin Stereo ELOP is an overall great choice. It has a price that will scare home studio owners, but has a sound that won't sound compromised by professionals. It has an extremely realistic tone and is perfect for those professionals who are looking for quality regardless of price. Considering that you are getting two channels here, the price is definitely reasonable considering the top notch tone available here. All in all the Manely Langevin Stereo ELOP is an impressive piece of gear that should definitely be of interest to professional engineers.