I've moved back to Xpres mugs after ditching the 10oz Orcas from MDP and Neil Bros due to being badly warped for the last 6-9 months.
There will be a fair few Xpres mugs with chipped/ bad bases, I would always reject those because the customer will complain. The odd dimple on the handle I would let pass. Any deep dent or dimple in the print area, I would normally reject too. I would only attempt to reuse as a last resort if my design allowed it.
I would say that Xpres mugs are the best of the bunch at this time.