Is there still any fan for the NYSE specialists? Their fills are terrible. This is not the first time. If my stop order is fill, island always fill it within +/- 1 or 2 cents. But if the order is filled by NYSE, it is always much farther than the stop price.
Why do you think NYSE fill is bad? The specialist has nothing to do with this. Check what NYSE quoted at that time, and I bet it was 50.44 NYSE is not always and doesn't have to be at NBBO.
This has nothing to do with the specialist. The specialist hardly takes part in these small orders in the new hybrid market. The vast majority of matches are done in the electronic book - just like ARCA/INET etc. If Level II is showing INET at top of book and NYSE is a nickel lower, then when your stop is triggered and it sends a market order to sell, you will take out INET and then get filled for the remaining on NYSE a nickel lower. If NYSE was on the inside, then you would get filled there first and the better price. If you send your stop order to NYSE, and INET is on the inside, they are required (reg NMS) to route your order to the best quote (INET).
if inet is showing 100 shares at the inside price which is a better price than NYSE, they're required to route 100 shares there, but even if the next NYSE bid is 50 cents lower and an inet bid that is big enough to fill your whole order is a penny lower, they will send your order to the nyse 50 cents lower.