I remember when he was first announced to play the young Obi-Wan around 1997 and thinking: "the Trainspotting guy? How's THAT going to work? He's nothing like Alec Guinness."
Turns out he did quite a superb job both paying tribute to Guinness as well as forging his own interpretation of the character as a younger man. Ewan and Ian McDiarmid were clearly the best things about the PT.
I will say, though, I thought he played Obi-wan a little TOO much like Guinness's older version of the character. I have a hard time believing Obi-wan was always
that much of a stick in the mud, who was acting like a boring old man even when he was in his 20s and 30s.
When I watch ANH, I get the impression of someone who actually had much more of a rebellious streak in him once, and was maybe even a bit of a smartass like Han.
I just never imagined the Jedi would all end up being as incredibly serious and dull as Lucas eventually made them.