I have owned my 200D sence September 2001. They are great airplanes. They are especialy good for cross county flights with good speed and the capability for long legs. I usually fly at altitudes from 7 to 9,000 MSL. My opinion is that my Meyers is very stable, it can be easily trimed hands off, and it handles turbulence very well.
I switch fuel tanks every 20 minutes so the fuel is balanced well enough for the factory aileron trim to trim out aileron pressure for wings level flight. I keep track of the fuel burned each time I change tanks. My wife doen’t appreciate engine hesitations when the fuel is exhausted in any one tank.
My partner and I looked into the 550 engine when we had ours overhauled but the engine overhaul facility convinced us that the 550 didn’t hold up as well as the 520 based on comparisons when they came in for overhauls. I understand they are basically the same engone except the 550 has a longer stroke. I imagine there are many opinions on the 520 vs the 550 and there may have been improvements in the 550 sence the time of our overhaul in 2003. Instead of the 550 we opted for performance enhancements which achieved 304 HP at 2800 RPM with our engine.
I hope you have great succes in your search for a Meyers 200.