I've been looking at this module for a while, and pretty pleased and glad that i purchased it.
two reasons, firstly, as a great mult, well made product, build is awesome, and has a rock solid quality. secondly its a summing mixer, and something that all eurorack systems should have, it makes sense to level everything off, with all audio sources working from the same starting point. and the 6db pad, also tones down and controls, maybe too hot and wild audio levels. the reduction of 50% is great to bring control to your sound.
and lastly, its a great module for cv sources and summing multiple signals, overall a brilliant module, well worth it and something that is a must have...
looking at second one for my system, as the 333 is so useful and versatile, and fairly priced.
as for pros and cons, no cons, all positive.