Quote - "I Wish they had made a Mike4-to-Mike3"

You mean like this ?  ;-)

(The other is my weightmapped Mike4-to-David 3)

Sorry, can't distribute him as DAZ are stricter about the V4/M4/K4 mesh than they are about the 3rd Gen mesh.

It was a bit complicated to make him, but as you see, not impossible. Don't know why DAZ never made one. Maybe the same reason there was no David-4 or a Luke/Laura-4. Simply not worth the effort.

I would have happily bought them - as would have a lot of other people.

You have to remember, after the YT's initial roll-out, DAZ released 1 item for them every 6 months.  There was 1 product that was zipped up in it's installers for 5 months before it was put in the store. 

Colorcurvature's M4/K4 script allows me to make Gen 4 YTs & a David 4, and, as an added bonus, the script will do the same thing with the Gen3 & Gen 2 figures.

Clothing has always been a "chicken and egg" issue.  Clothing conversion systems have been around for years, but most people wouldn't spend the 15 minutes are so to use them.  There is even an easier solution today with the fitting room in Poser 2014.

Oh, and 1 other thing - Just because in Poser 2014 subdivision can go to 8, doesn't mean that you can.

I tried it with V4, just to see what would happen.

Not only did I use up all 22Gb of my computer's ram, my swap file was over 18Gb before I pulled the plug on Poser.