I think Baikal has the right idea, manufacture a machine that can do many algos. Also the FPGAs are just starting to come out. Right now they can so the same algos ASIC resistant GPUs. Once the prices start coming down they will pose a serious threat to GPUs and ASICs.
There are already algorithms being developed to stop the threat of FPGA's. One in particular I'll share later after I learn more about it. I personally feel Hardware R&D does not give Software R&D enough respect. You'll be surprised what has already been developed and what's coming down the pipe.
I have a X11 X3 that is making more per day then a L3+ right now, and people called the X3 a doorstop.
There were too many other coins using the crypto night algorithm to make it a doorstop. I've heard others say the same. I knew better than to say such. However, the Z9 might become a doorstop "IF" Zcash forks along with BTG, ZEN, Bitcoin Private and EXPANSE. I hear EXPANSE is going to PROG PoW. There's a possibility the Z9 Batch 1 and Batch 2 owners might be alright. Those who purchase Batch 3 and later are doing so at great risk in my opinion. Not just from the threat of increase hash rate but from the threat of a fork to a new algorithm.
If you look back, every year someone comes out with a faster miner. I have had Bitmain, Avalon, and a host of others, I mine for a while then sell them off. I'm a hobby miner, I'm not in it for the big bucks. As long as I'm making something to cover the electric (yes ComEd loves me) I'm happy. When BTC and the ALTs were at their high, there is no way I would even think of buying a miner.
You made a wise decision in regards to not getting more rigs. Especially, when the price was at or near all time high; like my buddies did in Tennessee. They asked my opinion but ultimately made their own decision. They now wish they had simply used their funds to trade crypto. One invested $22k into S9's and L3+'s. The other one invested approximately $40k. I wish others who are new to the community would listen to those of us who have been in the game longer about when to get in and/or out of the mining game, upgrade hardware, etc...
I did buy 3 of the Z9 minis and a couple E3s at the cheap price. I will fire up the Z9 and see what they will produce, the E3s will be flipped.
I don't think you'll have a problem whatsoever with ROI. As for being able to mine with them several years later like I still do with some of my GPU's; well, you and I both know the answer to that.
There is so much wrong with crypto today, the biggest problem is scammers, DEVs who create coins to rip off people. Scams for miners that will never happen, Masternode scams and scam exchanges. These problems are hurting crypto way more then real manufactures coming out with new miners for ASIC resistant algos. They are making them because people will buy them. They are in the business to make money. Scammers are in the business of ripping people off.
I agree with your comments on corrupt developers creating scam coins, etc...
As for BITMAIN manufacturing ASIC's to make money (profit); that's understandable. They are taking risk just as those who buy their hardware are also taking risks. BITMAIN did not make them buy their hardware. It's not BITMAIN's fault people don't research and educate themselves to make proper decisions regarding their involvement with crypto; whether its's mining, trading or investing; such as ICO's.
You and I both are here educating people in an attempt to help them with the decisions they make in the crypto space. Yes, we both have different perspectives with you being somewhat pro ASIC and me being pro GPU. However, I respect your opinion and your freedom to express it. At least you do so out of respect and not resorting to personal attacks like some in the forums. Yes, you and I both have made little quips towards the other while showing support for our point of view. Yet you do so without taking those quips to a personal offensive level. Thanks for keeping it "real."
What is going to happen is going to happen, you or me are not going to change it. If some farm in China calls BM and says I want 10,000 machines for XYZ algo you think BM is going to tell them NO, THAT'S A GPU ONLY ALGO? Hell no!!
My only comeback would be; "There's nothing BM can do to fulfill that potential client's order if software developers have rendered an algo virtually ASIC resistant or at least made ASIC's pretty much on an even keel with GPU's.