I noticed that ORBX still has a lot of titles that it designates as needing an update. There were various airports in that group as well. It also seemed like 5.1 may have exacerbated the issues because of Truesky/EA. Even GSX needs a bit of an update for company-specific texture rendering. Also, I was having an issue with a Justsim airport, but I don’t know for sure if it was a 5.1 thing or a GSX issue.
Overall, I’ve got the A320 - so I’m good!