I have an F-30 and really like it. There is enough gain available for most styles (except for some metal tones) and the cleans are very nice. At extremely low volumes (apartment friendly levels), the amp sounds a little dark, but you don't have to turn it up that much louder before it opens up. I can't comment on the effects loop or how well it responds to pedals because I don't use them much.
I have not had an opporturnity to gig with it, but I did get to try it out at a band practise. There were a couple guitarists, bass, keyboards, vocals, and drums, and I was able to cut through just fine. I used to have a Laney VC30 1X12 combo, the Mesa F-30 sounds louder than the Laney did.