Overall, I have found SU5 and the Hotfix to be nothing short of spectacular for me - with 2 exceptions:
The “dancing reflections” that you mention. I think this has been caused by lack of synchronization between the layer they are rendered on, and the layer the world is rendered on. I found it so annoying initially, that I too turned reflections off. I’ve now got used to that, and think in retrospect that reflections “as were” were a tad unrealistic anyway. They were always too sharp, and existed no matter what the water state or draw distance. With them turned off, I think the overall appearance is a bit closer to reality.
Cloud “reflections”. Even with reflections turned off, some of the cloud reflections on water simply don’t match up with the clouds that are visible. They now (sometimes) appear as huge white “blobs” on the water surface unrelated to anything in the sky and - imho - can be annoyingly unrealistic. And I’ve found no way of turning those off, sadly.
But apart from those niggles, I found the overall sim experience to be eons ahead of any other sim I’ve ever had (most, since 2004). For comparison, I still turn to my P3D (with my $5, 000 or so of Orbx scenery) and what I see in MSFS knocks the socks off it visually, and performance-wise.