Having close personal (including family) and professional links with flight crew in both LCC's and legacy carriers in Europe and the US, I can see no evidence that there are any significant differences between the basic professionalism and professional competencies in LC's and LCC's.
What I do see is commercial pressures that impacted first on ops management in LCC's, now being equally applied in LC's. These commercial pressures are translating into an increased frequency of human error incidents triggered by the processes described in my earlier post that are, to some extent, being offset by advances in flight deck technologies (for example TCAS).
My belief (intuitive, not proven) is that this has created a sort of fool's paradise that has made it easier for airline management to believe that they can put greater pressure on crews because the technology is sidelining them.
I believe this to be a fool's paradise because I don't think that the compensating safety gains from technology will continue to be significant, whereas oil prices and competition is increasing the pressures on management to look for savings (and even more so looking to personnel savings because of their high technology investment).
I believe that the result of all this is that we are seeing the beginning of a trend towards increasing frequencies of critical incidents in phases of flights where flight crew (and others such as ATC and engineering) judgement is most significant. That means primarily on the ground and close to airports. Whether or not this forecast is correct will become clear in another year or so, but just look at the figures on runway incursion incidents and you'll see what I mean.
(personal disclosure - Son flying for an LC and a daughter in law for an LCC - so I'm not an apologist for either side!)