The barrel plug seems to be the weak link in getting sufficient power to the ports. I soldered the power lines directly to underside of hub pcb.
So getting power to the hub is typically the bottleneck, not the components in the hub itself?
That is what I have found. IMO don't bother paying more than $5-$10 for a usb hub, you are paying for the psu/ power brick/ wall wart that comes with it when you pay more, and unless its >10(550ma), it's not going to work for more than a few ports anyways. The PI needs around ~750ma as well, a usb fan is going to suck up another 500ma or so, using wireless on the pi will add another 500-700ma. Add it all together, does it total > than rating on psu?