It can be very difficult to describe what one hears in a meaningful way, so often I use terms that have fairly specific meanings in a general sense.
As you know, dynamics are not just a matter of over compression or even levels, though those are certainly key. Dynamics is keeping the emotion within the performance... emotion that comes with the way (intensity and speed) a guitar string is played for example.
In this the compression/level envelopes used tend to deaden that impact. The guitar is clear, but too even, and too loud. Robbies vocals are pitch perfect... but again too even. Guitar and vocals compete for dominance. Only robbies vocals should dominate... all else supports that. This isn't a rock song, its a ballad.
By way of example, there are a few live recordings of Simon and Garfunkle performing "for emily , whenever I may find her" that provide a good example of what I mean (simon on acoustic).
In retrospect, this may also be a performance issue, but it sounds more like mix to my ear. There is a lot of noise on both robbies vocals and the guitar... actually, when the bass comes in as well. With robbies vocals, the noise sounds like mic distortion (to much gain or an unflattering mic - but knowing what I do of robbies equipment it seems unlikely that the mic is the problem. So perhaps there is too much gain on it. But....
But, there is the same noise on the guitar. And a similar noise on the bass when it peeks. It could be clipping, but it sounds more like intermodulation distortion.
EQ wise, the mix is too mid heavy. Again, it is very clear, but it is a bit harsh. This is the richness component. It seems to me you have pulled too much off of the sub harmonics off the guitar (and even a bit off robbies voice) that then makes the sound a little brittle to my ear.
I feel it is these things that are perhaps causing the affect of the song to be weakened for me.
Hope that made sense, and helps a bit. Please do recall, much of this is subjective. When I comment, most often I am not trying to tell you what to do, but tell you what I hear.
Cheers
Shad