well clerks 2 is significantly better than both dogma and J&SB. it obviously has lost the indy feel of the original, but it follows similar themes and ideas, (being a directionless loser, talking shit with your friends and most importantly, girl problems), so it still feels very clerks. i worried that they'd fuck up transplanting the spirit of the first film across to the sequel, but, for the most part, they did a very good job.
overall i think it's a very worthy successor. there are far more "hit" than "miss" moments, and if you enjoyed *any* of kevin smith's work, you should give it a try. it's definitely one of his best flicks.
oh yeah, i have to add that jay and silent bob are funnier in their bit parts here than they were in the entirety of their own movie.