Why? Wouldn't it be easier to repair since they're not buried in walls?
I lived in a building that had persistant plumbing problems, the leaks were easy to find as they occured inside the walls and in the ceilings which caused the drywall to sag or deform. If a leak were to form inside the floors under a raised flooring system, the concrete slab would act like a shower pan while the raised flooring would be above the leak.
Actually today I visited the sales office and the raised flooring system that was touted in newspaper articles were extremely downplayed at the sales centre, to the point it was never mentioned. I had to ask about and even explain it to one of the sales people there as even they didn't know much about it. The raised flooring system is also dumbed-down in the unit design as it only occurs in a small portion of the unit. It only happens at the foyer, bathrooms and some closets, which creates one or two level changes within the unit.
Back to plumbing issues I think it wouldn't be an issue here as if a leak were to occur I'm sure it will seep into the areas that do not have the raised flooring thus signifying a leak before the problem becomes serious.
I am not to fond of the level changes as it creates an awkward two steps up to the bathroom and some closets from the bedroom right at the door opening. It allows for some flexibility to move plumbing within the raised portions of the unit, but you will still need to build up a platform if you want to move plumbing to the areas that are not raised. I am not really buying into this raised flooring system, as you could later build a platform in any condo unit to run the plumbing laterally -- not the most elegant solution as you lose ceiling height and creating awkward level changes.
Otherwise it is a nice development in a nice quiet neighborhood. The selling prices are reasonable (they are offering a discount equivilant to 18 months of condo fees, free assignments and renting at occupancy only until the end of the November), the finishes are tasteful and nice, and the building is nicely scaled with less than 90 units. I'd like to see more balconies on the prime southern park-facing units (most of them only have juliet balconies).