buy only batch 1 of any bitmain product is moral of the story. d3 is negative, a3 is negative, l3 is also negative now.
The only thing that makes more than $1 a day is the x3, which is an extreme high risk coin, because coins using cryptonight are actively forking away from it.

i personally have a z3 mini on order (1st batch), but wont be buying an august batch even though i can get it for $600+shipping after coupon.