I've done a number of drops with Massdrop and now Drop, for a variety of items. The shipping time and communication has varied a bit, though has generally been acceptable to good. I ordered some of their Sennheiser x Massdrop HD6XX - two times - and both of those went smoothly.
They've never let me down, only kept me waiting a time or two. Sometimes, that (longer lead time) was known at the outset, a time or two it was the supplier, i think.