A watt is a watt. But the production of that watt can be different.
And no. As danb said, it's not that simple. But I'd disagree about having a low kenetic energy trainer. That would trash my legs. As the pedal stroke would be different to on the road, recruiting different muscles.
Hmm. My creative (and very un scientific) brain is struggling a bit here.
Simple Q: I have a Kurt Kinetic Road Machine. I've always got on very well with it and it doesn't feel like pushing through treacle. Do I need to spend more money on a new DD trainer?
So, are we saying that doing longish threshold efforts on one of these gives greater gains than on a fluid trainer? Watts are watts, Shirly?