
I've replied by pm to the OP, but will answer your questions here too for anyone else interested :-)
1) I have four dogs-how hard wearing-does it hold the smells-does it fade in colour.
Mine has a borzoi, 2 collies and a silken endlessly playing/digging and going to the loo on it. The girls race round playing tag on it and it still looks exactly the same as when I put it down 4 or 5 years ago. Yes, it does smell if not hosed down with bleach or disinfectant.
2) How does one clean the turf.
Poos just sit on top and are easily picked up, I hose mine down every few days in the summer either with bleach (straight from the bottle held over the water stream) or disinfectant and that does the trick and the grass has never changed colour. In the winter it can go weeks without being hosed and doesn't smell.
3) What depth of grass is the best to get-seems to be short-medium-long
I think that depends on how you wan tit to look. Mine is 35mm.
This is the stuff I have, apart from being incredibly heavy to install it's absolutely brilliant.