SeanMI tipped Big Tim off that this thread would polarise opinion! However I think you're right, the consensus is much as you've stated.
Personally, although I've weighed in on this thread as an ardent supporter, I have to say that it's a long time since I've considered him a viable live performer. It's no longer his milieu and it's a sad indictment of the rock'n'roll industry that they continue to push him in this direction. (Having said that, I really don't think the guy is going to be giving too many live performances in this lifetime.)
I'd say listen to the albums – the first three Pogues' albums to remind yourself how they matured as a band and "The Snake" and "The Crock Of Gold" to hear how Shane, operating in self-aware mode, got to the essence of his world-view. The latter album in particular may not be comfortable listening, but is the (more truthful) alter-ego of "If I Should Fall's" (relative) polish and sophistication.