Half of Puck's lines--the older ones--are excellent, but half of them sound like a forced, overdone imitation of his older lines. Really, the new lines wouldn't be so bad if they weren't thrown into stark contrast with the old ones. You might not notice bad voice acting if that's all there is, but switching back and forth between great and awful is noticeable and jarring.

Examples...
Older, good:
http://www.dota2wiki.com/images/1/1c/Puck_rare_01.mp3
http://www.dota2wiki.com/images/8/86/Puck_kill_10.mp3
http://www.dota2wiki.com/images/3/33/Puck_death_10.mp3
http://www.dota2wiki.com/images/e/e7/Puck_spawn_06.mp3

Newer, bad:
http://www.dota2wiki.com/images/0/09...ebegins_01.mp3
http://www.dota2wiki.com/images/f/f4/Puck_rival_12.mp3
http://www.dota2wiki.com/images/9/97...op_rare_01.mp3
http://www.dota2wiki.com/images/8/82/Puck_rival_05.mp3


The older lines sound playful and a little bit sing-songy. THE newer LINES sound LIKE the VOICE. actor HAD a... STROKE!