My friends and I have order from Black Arrow since November. None of us are getting weekly updates from them. Further, one day after they announced the delay to May, we requested refund immediately. For me, they said "your request in the refund queue". For my other friends, all enquiries had been ignored.
Sure, I know HashFast was terribly behind schedule. A guy placed his order in August eventually received it in January. I placed mine in December and I got an email from HashFast last week Tuesday that it will delivered in March. So, I'm glad.
CoinTerra, same story. I placed my order in Dec. and looking at their updates, I thinK I'll get my machine in April.
HashFast executive interview:
https://www.youtube.com/watch?v=5yj-mmnRWYcCoinTerra's CEO was formally from big company. He is well know, can be verified and has a LinkedIn profile.
Alright, if Black Arrow turns out to be not a scam, I'll order from them. I will visit their factory to verify (after they deliver) and will probably resell for them. :-)