I find the people that complain about others working from home are the ones that could not be trusted with the benefit themselves.
It is the way of the future. Every communication is done through headphone and email, there is no reason to physically move your seat to the office unless you are hands-on, or immature and in need of warm fuzzies all day long.
An office visit quickly displays those who walk around looking for someone to b---s--- with, gym work-outs, long walks for exercise, long lunches and several breaks. At home, it is quiet and focused. The majority of time it is many more hours than would be put in at the office in a little gray cube.
Most large companies have this benefit and know how to save capital by offering it. It they don't, they are just behind the times. Better get used to the idea. In-office jobs are no longer - look around.
And if there is someone working remote that you can never get support from or is never on-line, report them as you would if they were in the office. Those people would be slacking no matter where they were sitting.