As pointed out, "overpowered" is a relative term. Pun-Pun is completely balanced in a group of equal power level and inside a campaign that can handle them. In games that I play in, your standard Daring Outlaw would be putting out the best damage in the group just on 19 BAB and +10d6 SA alone. Find what's balanced in your group and that's all that really matters.
Personally, what I care the most is for classes that are fun. I would never play WOTC's Daring Outlaw even if it was balanced in my group. I find the class incredibly boring with a lack of options. I would play jiriku's version because it has variety. Now, variety in itself is powerful, but you can always tweak the crunch to find a suitable balance point that you're happy with.
Example:
All Bob can do is swing his sword against an enemy. Joe can swing his sword, do a spinning bird kick that dazes opponents in a radius, punch casters in the throat to silence them, and verbally convince opponents to kill themselves. Joe and Bob are in the same group, so you might be concerned that Bob will feel crappy. You could just make Joe's 4 options 75% effective to Bob's 100% effective 1 option and call it a day for relative "balance." Actual numbers subject to change, but you get the drift, right?