I did this last year and my neighbor and chem lawn and is grass was green and thinker them my. .
I ponied up for it this year and had to haggle with them a bit on the price (then wanted $65 ened up paying $42 and my yard is over 12,000 sq feet.)
Am set up for 7 treatments plus they will come out whenever I have any problems.
Also the said the yard is usuable 2 hrs after they are done. NOt sure how true that is thou.