A sample size of one, admittedly, but I haven't been terribly impressed with Sand Hill. I placed an order for 25 chicks from them last July and am still waiting for it. I emailed them before I placed the order asking about availability (at that time their last update on the website was from March) and got no response. They didn't end up updating the website until all their hatch dates for the year were passed, by the way -- making it fairly useless. I had a Sep hatch date, which they missed, along with the rest of the fall dates. Moderately annoying, since we butchered our existing layers to make room for the chicks in the coop but they never came. I've called them twice during their narrow "call windows" to attempt to see if we could get an idea of when this year we could expect the birds so we didn't have to be home every other wednesday for the rest of the season, and have yet to have anybody answer. We got some chicks locally early this year, raised those in the brooder, and then sold them off a few weeks ago figuring it was easier than having to scramble to clear them when the new chicks came. I should have learned my lesson, but apparently I didn't, as both March and both April hatch weeks have come and gone now.
I'm sure they've very nice people, and I appreciate their efforts at preservation of rare breeds but they are clearly stretched too thin to competently handle the volume. I certainly have given them a lot more leeway than I would a normal commercial hatchery and I suspect others do too. But I can't be the only one who has these issues. Be wary.