Possibly so, but I think based on a lot of experience with drops of Esoterica from both SP and Top Hat that the latter handles them better if you judge by "oops, we oversold, sorry" messages received hours after confirmation from both the vendor and PayPal. SP leads there 3-0.
This is a different world than it was just a couple of years ago and it is entirely possible that the demand for unicorn tobacco combined with the speed people hit these sites due to bots, scrapers, email alerts and social media has stressed even well designed inventory systems in ways not foreseen. Many of the players, if not all, have bought systems from someone else and can't make "simple" adjustments on their own. I think we all ought to be a touch more patient with, and forgiving of,vendors.