hi guys, what are your fellings on thinseting cbu, wonderboard directly to 3/4 x 4" floorboards. or should i put down plywood first ,then carry on as usual. the largest tile will be 20 x 20. there is a bit of a height issue though, 2 rooms with 3/8 hardwood,the front door & threshold & a hallway with carpet, well no worries there. anyway, any thoughts on Ditra, what are its limitations, pros & cons etc. i have never used the stuff. all input would be greatly appreciated, thanks.