If these were available now... or even by the end of this year... I would get at least 1 of the DCR models as currently it's $170 net profit/day so only about 2 weeks to ROI.  Unfortunately, there are a couple of big drawbacks with these.

1- Won't be shipped until at least mid-2018... so about 8-9 months from now lol!  This is a complete joke imho.  That is FOREVER in the crypto world... so much can happen that could make these defunct upon shipping. Most notably is the increasing difficulty of DCR.  It's already spiked bad in the last 2-3 months and although it most likely won't get ridiculous to the degree that DASH has recently, 8-9 months is still a VERY long time. It's entirely possible that DCR rewards will be down to $10/day by the time these ship, meaning they will never ROI.  I guess you could make an arguement that with ETH mining almost done, DCR diff will stay relatively flat since I think most people are dual mining ETHash & DCR, but there are still some other ETHash coins that will likely remain profitable to mine... esp if AMD can get their damn drivers fixed for Vega... and more Vega's hit the market... so this just seems really risky to me.

2- I have a big problem tying up $2,500 in capital for 8-9 months.  Right now that's about .33 BTC but by mid-'18, BTC could very easily be at $15k... meaning I effectively lost $2,500 off the bat... then probably won't even recoup the other $2500 due to what I mentioned above.

I would suspect that this is why they haven't sold many of these yet. Seems WAY riskier than even recent Bitmain releases... and look what happened with their recent LTC shipments.

I would say there are 2 much better options to use $2500 now.  1- build a 4x Vega 56 rig and either dual mine ETC + DCR or put it on XMR/ETN or other cryptonote coin.  or 2- just invest it in BTC or another coin.  2 months wait i would do it... 8-9 months? no freaking way!