There isn't anything that you really need to know about using the API Audio 500-6B Lunchbox, as once you've got it set up, you're good to go. It isn't hard to place the modules into the 500-6B as they slide right in without any problems. I don't think that you really need a manual, but if you're new to the make up of 500 series racks and cases, it might be a good idea to have it around anyway.
There isn't anything at all that you can judge the API Audio 500-6B Lunchbox on sound quality, as it is merely as casing for 500 series modules. No sounds whatsoever are made or processed through this piece of gear - it only houses modules that do. It doesn't have the means to color or add to any of the sounds that you hear in the modules either...
As far as 500 series casings go, the API Audio 500-6B Lunchbox is one of the best out there for a few different reasons. First, since API does manufacture most of the 500 series modules out there, this casing is absolutely fully compatible with their modules and other out there. They really invented the lunch box and 500 series design, so getting it from the source isn't a bad idea. It is also great that it comes with the power supply, which is a considerable amount of money if you need to buy one on its own. So even though you might have to pay a bit more for this 500 series casing than you would another, it makes up for this with the power supply being included. If you're looking to put together a 500 series rack, I'd highly recommend going with the API Audio 500-6B Lunchbox.