There is no harm to use them Colm, ultimately you will have a cleaner throttle body, intercooler, pipe work, turbo etc etc...
It's the like of track use or launches is where the oil can effect the clean burn.
For example I had an sti6 and if I launched it hard, the next morning when I start it up it would fill the yard with smoke... And then clear...
Reason was when I launched the car, oil was coming up the crank breather, under boost then it would stick to pipes and intercooler, when it would be left stopped for a while the oil would get to pool and that's what I was getting on start up, that pooled oil burning off.. Catch can sorted that.
If your doing a lot of short journeys and town driving you will find that the can will fill with a rather horrible looking water.