Mark,
Some of the jobs that i have done in the past have been very light soil and have managed UPTO 200sqm. I certainly couldnt do that now as age is catching up (36). Realistically 100 - 150 sqm can be done with a wand. This would be done without the compromise of quality. I used to clean nightclubs 5 days a week with a wand (before the glide days). Once you are used to it then it gets easier, although most clubs were in the region of 1000sqm - 1500sqm and had to be done in 1 day (2 men, 1 wand, 1 TM). We were knackered at the end of each day.
Richie.