It's a good thing to have available and I've used it several times - but I don't use it anymore and just call an arborist directly when I need chips.
I stopped using it for several reasons, lack of communication was the biggest issue I had. It's a blind service and you don't know who's going to fulfill the request, it's up to them to contact you and let you know when they're coming, what they're bringing you, etc. Several times I had zero communication other than seeing an email pop up while I'm at work, that my drop request was fulfilled - then come home and find half the pile is on the street - so you go to shovel some off the road so people can drive by, only to find 100lb logs hidden under the chips. Other times I got mixed stuff inside the chips - palm fronds, ivy and vines, loads of all small ramial green foliage instead of woody material (decomposed really fast and pretty much composted itself), lots of trash, a full load of cottonwood (it smelled sooo bad), etc. I'm sure there are some great arborists out there who use Chip Drop and provide a much better experience, but apparently not the ones who I got half the time.
My experiences calling up an arborist directly - significantly better and I haven't used Chip Drop in a few years now since doing this. Actual communication giving me advanced notice when they're coming, as well as telling me what type of wood it will be because they knew I was using it around chickens and fruit trees, etc.
So yeah, my recommendation is to just call an arborist and ask to get on their private drop list
