What do yo guys think, any cons to this setup? http://youtu.be/n7GdZ6rN1R4

Very labor intensive. With Polycrete's R-Stak Inserts, you do 16 sqft in the same amount of time it takes to put in one of those little sticks.
https://www.facebook.com/video.php?v=10152295685945590&set=vb.246132040589&type=2&theater

i would like to use them on the outside of the wall to keep the thermal mass inside.... Would this 5-6" of foam have an negative effect on the mounting of natural stone veneer and stucco? would it be stable enough?

You install the extra insulation to the outside of the concrete, thus keeping the thermal mass closer to the inside. Fastening strips stay towards the outside surface as they normally would be. Nothing changes for that perspective.

My thoughts are that with the concrete not casting in the plastic webs eight I the edge (2.5" away) it would make te outside of your building less ridged.

Any issues with stucco cracking or is it pretty proven?

Thanks

I can't speak to plastic webs, Polycrete's fastening strip and cross tie system is steel, so it's plenty rigid.

As I've written before there are several knock down blocks that the foam can be increased with out too much trouble and less cost

I like the idea of extra insulation on outside but my concern is that the cavity for the concrete now is narrower and it will make pouring and consolidation of the concrete more difficult? Unless used with wider form 8" instead of 6".

You up size the block to make up for the loss inside.. With a system like TF you can move the foam to the outside and keep the core width the same.

With Polycrete Big Block ICF, you can have a core width up to 24" so you can add up to 18" of additional insulation all the while keeping the fastening strip the same distance for the surface of the wall and maintaining a 6" concrete thick concrete wall. Not sure why anyone would want that much insulation, but it's the technological limit of the manufacturing system.

Logix block works fine with the additional insulation it is basically a slide into the inside face(concrete side) of the outside panel, has no affect on fastening items to the exterior the inserts are 2" increments, so if you have a 6" concrete core wall the ICF block size would be the standard size if you want to add 2" you will need the 8" ICF block, simple. almost all of the manufacturers are pushing this product now and why not they are in the business of selling foam and it does make some sense? As you might expect the ICF manufacturers have jumped on board and trying to constantly separate themselves from one another-each has come up with their "very unique" version of accommodating the consumer. if you dont plan on doing icf for a living and you are doing it yourself, there may not be a big difference for you, you have plenty of time and "its your house and you want to do it right", so product type may not be as important as price. However, from an installers perspective, there are huge differences in installation, none that i will go into in this forum, but suffice it to say, if you do plan on "subbing" this out, before you FORCE a system on an installer, especially an experienced one(i would strongly suggest you check their ICF references) , i would talk with them first about the systems they would suggest, since they have practical experience with the system. To their credit there are some pretty savy and persuasive manufacturers and mfgrs reps who can do a pretty good sales job on you and before you know it, you have purchased material WITHOUT an installer on board..that is the kiss of the death my friend, or at least putting the cart in front of the horse!
ICF's are great house none the less and i have not had anyone that would not build it again and use ICFs, i have had people tell them the path to an ICF house can be quite an experience though.
Wish you well and you are on the right path!

Bill is correct on all counts.

From a Fox Dealer's point of view, they aren't hard to do. They increase the R factor significantly and every one likes to sell more product , but, I always tell my customers that the return vs the investment is reduced after an R factor of 23 or so. I would rather they put the added cost in a better window or door system. Up size the form and drop them in. A little more stuff to store on site and less room in the shipping van.