Mesas are muddy when people don't take the time to learn how to use them properly. Played moderately loud (or attenuated, I suppose) they sound pretty damn tight and focused. It's also extremely important to bias them correctly to get them out of crossover distortion, which is the cause for the fizzy tone some people complain about. I'm not a die hard Mesa fan. In fact, I don't own any Mesa products. Yes, they're so fucking overpriced in Europe, but I just think it's foolish to label Boogie amps as muddy just because you think Linkin Park sounds like shit. Every time I've played a Boogie, it sounded fine.