11 o'clock show was his level: naturally funny personality without much talent for jokes or the creativity to turn it into a craft.
The xfm and podcast stuff is very funny and his class clown on high act, making the sidekicks the butt of the jokes has been very influential in the medium.
The office is an excellent comedy, well produced with good characters. Watching it back though you can occassionally see some awkward mawkishness - that would later become the Gervais trademark - creeping in. The comedy does a lot of work holding up some pretty low grade dramatic clichés at times. It's still often brilliant and I don't think you can simply attribute all the best stuff to Merchant, even if subsequently the evidence suggests that he has a far subtler pen and superior gifts as an artist. His Brent performance was the main thing that elevated the show, it was lightning in a bottle stuff. Everything else became progressively worse.
The stand-up was always of the mediocre club comic standard, and he seems to lack the awareness (possibly blinded by the money and success) to work on his deficiencies. The attempts at lofty themes were only ever superficially referenced, serving more as pretentious placeholders than explored premises. He saw himself as a Stewart Lee or Richard Herring: artistically ambitious, thematically complex comics that produce carefully constructed routines, but he never developed the craftsmanship skills to produce a show in the way that they do. You can find Gervais funnier than Herring and prefer his shows but you could never say that they are doing the same type of work.
The transphobic stuff is par for the course. The disabled, fat people, foreign cultures or anyone disadvantaged were always punchlines for Gervais. Even when he was being ironic you could tell he sometimes wasn't. But being a cnut isn't why he lacks credibility as an artist and writer and why so many in the industry see him as an imposter who hit the lotto. He is routinely dismissed because he doesn't belong and never has. It's not just that cadre of sensitive lefty brit comics that mock him as talentless and hacky either. Listen to any of the multitude of comedy podcasts over in the US, from across the comedic political spectrum, and you can hear frequent, off hand dismissive remarks about his work. Most - outside of his rich celebrity mates - seem to hold him with a degree of contempt.
He did well for himself, particularly given his lack of talent. Not quite stolen a living but theres a level of fraud at work. He is popular for the same reason that ladbible survives. Taste and quality rarely align.
As Armando Iannucci said at the 2005 comedy awards "You peaked with the wheelchair stuff Ricky".