Been using NG for several weeks now, I subscribed prior to buying airports so my analysis will be based on having NG In place. I don't really use the default data as it's a nightmare to sync with simbrief, stkp. I could not live without NG since using it.
For ESMS previous NG Airac had no Data, current one does. Default data not sure if that worked or not as I never tested, I also never flew to this airport using default scenery.
LEBL missing ILS on runway 7 I reported to NG support and they confirmed this was indeed a sim issue given that it's not a selectable runway in the MSFS planner, not sure if that's fixed since.
For the ILS issues I did report to NG Support so far those were not actually related to NG data itself and their support staff was able to provide evidence of the issue being sim related but fundamentally I am confident in claiming that I have 'less' issues with NG data when it comes to ILS's missing from airports compared to the default data based on my usage. This is then resolved by using NG and that's not based on my own comparisons between the two, that's based on others reporting missing ILS using the default data and me subsequently checking at my end using NG to find that I do have ILS data.
Given that NG for msfs is technically speaking still in beta and with this amount of airports my exposure is undoubtedly limited and there do seem to be a lot of moving parts here, custom scenery, runways assigned with airports in MSFS itself and then the AIRAC data so I'm sure that the mileage of others may vary.