My L3+ Miner came in today! Yay!
Congratulations

My L3+ miners have been a good investment so far. They manage to earn about $600-$700 each per month, pointed at NiceHash's servers.
The D3 (which arrived about a week ago) aint so great presently. Due to an increase in mining difficulty, it probably manages a mere $150-$200/month, which is barely more than it costs to run. However, since there's not much else to compete with for X11 mining, I would expect the price of X11 coins to rise in the near future to reflect the mining costs, so I'm mining Dash directly (which I plan to hold, at least until it increases in value).
I have another L3+ on order, which is due to be despatched next month, and I ordered another S9 from the January batch too. While the S9 isn't quite as profitable as the L3+, I think they're a good long-term investment still. Even if a newer, more efficient model, is released soon, SHA256 is so saturated with mining power already that I think it would take a long time for it to have any effect the profitability of the S9.