Never had a good experience with them myself, but other people seem to rate them. However for the price I've seen the Avons, you can usually get F1 Asymmetrics or Vredesteins.
However, I'd consider them a 'budget' performance tyre (despite being the premium 'performance' offering from most wheel companies when you want to upgrade from their ditchfinder 'performance' tyres), and go for Hankook/Falken/Kumho before trying an Avon road car tyre again (they do decent trackday, motorsport & motorcycle tyres though).