IMHO it is one of those internet myths that gets spread around with out a lot of facts. Nitrates come from Nitrites, which come from ammonia. The ammount of ammonia that is produced is the same no mater what type of filtration you are using so the ammount of nitrites and nitrates will be the same as well.
The problem is that people do not clean their filters out or change pads nearly enough. This detritus that gets trapped in the filter rots which creates more ammonia and thus more nitrites and nitrates. It has nothing to do with the bio wheels but rather the extra dirt trapped in the filters.
IMHO biowheels are a very good idea, just be sure to keep the filters clean. Marineland also makes a bio-wheel system that is powered by just a powerhead. There is no filter, no pads not anything just a powerhead, a spray bar, and a biowheel(s). The powerhead does have a sponge prefilter on it, but that would be very simple to keep clean. I would think that one of these would be ideal for a reef tank.