Having Conner as a heavyweight crafter gives me a fair bit of insight on a number of things regarding differences in items, but sometimes you don't notice everything until you make a new character and try a new idea out...
Yesterday, I launched a new alt who is a nunchaku wielder. Nunchakus, as most know, require the exotic weapons feat to wield. Exotic weapons typically have some combination of advantages over their martial counterparts, including: maybe slightly higher damage, an extended crit range, some bonus skill points, a smaller size category, or maybe even a bonus combat feat.
The problem appears when you start RPing and eventually go to upgrade as part of your play. It seems the crafted nunchakus lose the parry bonus entirely. Aside from being 1 pound lighter, there is almost no difference between a crafted nunchaku and a crafted club... which pretty much any character can use anyway. They do the same damage, they have the same crit range. The nunchaku is one size category smaller, though, but that alone makes it hard to justify the exotic weapon proficiency feat.
So, at the risk of now sounding a bit self-serving, I would suggest the following:
--Give crafted nunchakus the parry bonus like many of the other regular and "magic item" nunchakus OR maybe give them a 19-20 crit range OR a higher crit multiplier
--Give crafted (and all) nunchakus the improved disarm feat (I've also seen separate threads about this for whips - it's a pointless feat bonus here, since everyone gets it free anyway)
There are probably other examples of this among the other custom exotic weapon types (I haven't crafted one yet, but I'd be curious in the sai is in a similar boat).
--Matticus