Ummm, oh well I do not have my Ton Po's yet but to be true except for the HP, +attack and +regen the stats are pretty bad. Well some might tell, attack + HP is all for a monk. I say I'll better keep the WoS common bracers then doing any efforts getting those. +str and +agi and better resists and I would be a very very happy monk even if those had only +10 attack then ;)
It's a bonus. The intention was to make a dex sta bracer, obviously, not to make a str dex sta agi bracer for exp. and we got cha as a bonus. Yah in all likelyhood it won't help you in a fight but for buying a stone, or some fizz formula or whatever it's nice if you don't have to carry cha gear/piece and just get a better price while attired in your regular street cloths so to speak. Yah I know it is probably a pitence to most folks now days, and probaly won't make or break a 24 stone limit but it could, nonetheless it's a potential "bonus" for any given person. It certainly doesn't hurt anything, and you aren't going to get to trade it for something better.