It seems to me that, at this point in time, the advantages and disadvantages of 2-way or 3-way are about even. Depending on personal circumstances, previous experiences, etc, the scales will tip one way or the other.
When ordering the Penguin, I did have a choice, but, in the end, stuck with a 3-way. It was just easier. But, since I have been in electronics for well over 50 years, my interest should naturally fall to a 2-way system. Also, of late, less use of fossil fuels is also of some interest to me.
In my opinion, if there is a step jump in the attractiveness of a 2-way system, it would be game over and 3-way fridges would become museum pieces. What do I mean by that:
1: 2-way fridges need a significant drop in cost and a marked increase in efficiency.
2: Solar panels need to keep reducing in price, increasing in efficiency, in reduced weight.
3: Energy storage technology needs to have a big increase in capacity, reduction in weight, and reduction in cost.
4: Energy management systems need to become more reliable and less complicated. The user should not have to carry a multimeter around to keep the system running.
As we know, there is currently positive movement in all 4 areas.
I have gotten use to my 3-way and it serves our purpose. But I am waiting in anticipation for some time in the future when it becomes brain dead obvious that it is time to upgrade. At the moment, for our usage, the improvement is only marginal at best. We have seen these step jumps in many other areas of technology. The RV market is huge and it just needs one company to bite the bullet and offer a revolutionary approach and investment to provide much improved solutions to energy management in this area.
Anyway, I am off to finish packing. Tomorrow morning, we are going to Vaughan Springs for three days.
cheers
Mike