Yes, spot on. It might be even better to compare photon output (µmol/s) than energy output (W) but this is good enough.
Neither PAR W nor umol/s on its own tells the complete story. I know that all research shows that photon flux density is what matters for photosynthetic activity, and not the power of the radiation, however this misses a very important part. (which i'm sure you realize)
Lets say you have a 35% efficient "grow lamp" where all photons emitted are 699nm. It's true that this 699nm lamp must have a higher PPF than a similar 401nm lamp with 35% efficiency, but this isn't enough to conclude that PPF matters more than W.
A 699nm lamp is going to do a bad job of growing plants regardless of it's PPF. If we could add energy to some of those 699nm photons somehow, it would shift those particular photons toward 400nm.
This means adding power. Having the right spectrum is why efficiency matters and not just umol/J. If we could make some of those red photons blue, it would cost energy, but PPF would stay the same. Unfortunately, we
need some of these blue photons.
Since we need so little blue, the spectral distribution of a good grow lamp will be heavier on the red side, and thus what I said above becomes a mitigated problem, but you still need blue (and more than one spectrum), so it's hard to outright dismiss PAR W while only looking at PPF.
