My quibbles are mostly game-play related. There wasn't so much of a story as in HL2, and also I thought the pace of combat was just too frenetic. Mostly, though, I thought some of the segments were just ridiculously difficult, which detracted from the game for me. In the end I gave up on the last segment and watched it on YouTube, and I never do that. I just couldn't be bothered to go on.
HL2 was hardly a leisurely romp, but there was more room to breathe and appreciate the scenery.
Keep them mowing blades sharp...