I'm looking for general knowledge in ICF's. Which is recommended, to use a concrete deck or wood for floors in ICF homes?  How much more would concrete be, say 2000 sf ranch w/ full basement. 

2000sq' is about $22000.00 for a concrete deck . off the hip price.

Engineered floor joists about the same, materials and labor

So, where you located and hopefully others will post with more accurate answers

Location and local labor market changes everything

thanks for responces. Not looking to build any time soon. Just searching options and what is best practices. Over wood deck or concrete - which is more commonly used, or is it split? Does anyone prefer one over the other.
How about asthetics of shell? Are options open to siding, brick, stone or are options limited?

 Well , look at $11.00 per sq' for (labor, mesh, concrete 3"slab, labor, pump, and finisher)
OK some places will vary but not that much(give or tack $1,500)

Still no location here but this is a start.
The benefits of a concrete deck are .
1.  sound transmission
2.  Large thermal mass for heating and cooling (inside tep. stays even slow to change)
3.  structural superiority (diagram action tyeing all the walls together)
4.  and a fire rating up to 4 hours
I hope this helps,
Feel free to Add anything here if I missed something . May be a price?

Woulfcc, If this was a slab on grade, how much would you figure extra (if any)? How much of the SF cost is labor? thx, Dave

 Now thats a good question.

 The last slab on grade I did had to have a soil engineer on site.

3 days excavating 40 trucks of bad soil removed and replaced with gravel and fabric and compaction.

After all was said and done $40,000.00 (that's is the unknown)

On a raised concrete floor I can be sure of the price of : concrete, joists ,mesh ,plywood shoring , profit , My guys my labor.

 With the flooring syt. out on the market today the labor has a easer learning curve than ICF's.
 Yes Mr Jonson I can say this is what it cost for me to do it. When do you wish for me to start.(travel is not inc.)