Ok so here is my preliminary report.... I'm gonna write up something proper later tonight. I'm on my phone so please excuse any typos.
First the bad: no R6, R8 or R9 domes, the R3w/Red was also MIA. They ran out of black right legs before I got there, so that made things limiting. The park employees were sympathetic to the problem, but could do nothing to help. Nor were they willing to take "cash for their troubles" and get me parts/droids at a later date. So I only ended up with 13 unique droids out of my desired 26.
The good: the staff was very friendly and happy to help. They were helping me throughout the entire time, grabbing parts that I needed from the other side of the bench, holding the droids behind the counter, etc...
The set up is very cramped, you can barely fit two people at the workstation and it's configured for two people to be building at the same time. You have to wait in line to get to the station, but there were more onlookers than actual people looking to buy.
Parts are shipped in assortment bags, kind of like legos based on how one team member described it to me. The problem is that the colors are all mixed and YES some pieces could be considered "chase" - for example she said that if a bag of right legs has 5 white w/blue markings but only one or two of the black w/silver. (I'll pause for a second while everyone reading this groans)
The shortage of the all-blue and all-black right legs was compounded by the fact that apparently they received twice as many left leg bags as right leg ones.
The did tell me they get new parts every day, so my hope is that when I'm there first thing tomorrow morning, there are more all black right legs in stock.
More in a bit, my cell phone battery is dying...