Quod Libet has lots of very positive reviews and, by the looks of things, a loyal fan base. From the documentation and screenshots I can see why and I was very keen to use it. My library is just shy of 40k songs and 290 GB and I was looking forward to finding out what QL could do.
However, having installed it and set up my library it has become unusable. Literally every mouse click results in a "Quod Libet (Not Responding)" message. When I say literally, I mean literally. It takes about 90secs to begin responding again but the next mouse click results in another not responding message and more time finger drumming.
I can see the potential and I would love to use QL but based on my experience I cannot recommend it.