Phil please let us know when they take your btc.
When they ship.
When you get it.
In my case, I ordered last Tues. By the time Canaan got to acknowledging the order on Thurs they informed me the 741's were out of stock with new stock arriving over the weekend. I chose to pay with BTC on Thurs vs waiting for confirmation of stock, tx was confirmed by Canaan on Fri.
As they promised I just got an email from Canaan saying miner has shipped.

I have asked them quite a few times for the bill My order was placed thurs.
So I guess I will be at least 2 days behind you.
This slow billing really is hard on me. coins are now 2768 they were 2830 when order was placed.
My fear is price drop of coin to 2500 and they bill with a 2500 conversion rate. Not the 2830 rate.
Not much I can do but wait for the bill.
I know they are fairly quick once you pay in btc.