You can check the issue number however; there have been occasions when the odd omission or error has occured on Skydemon so what assurance does the issue number really provide? It is not a certified source.

Yes, I have used Airbus FMGS and FMGEC (IRS and GPS referenced), on an almost daily basis for many years' airline flying.

My point is that a new pilot should be taught to use compass and paper map in the first instance, so that this most basic navigation is ingrained into their thought processes and situational awareness. For example when lining up on runway XX, for gross error mitigation they actually check that their compass agrees with the runway designation ATC just gave them, not the line on their GPS.

GPS and FMS systems are indeed wonderful, but when the electrical power goes or the GPS is jammed or there is a map shift, or the data base is out of date etc, one could get into a tricky situation if one does not have the basics always running in the background.

There might come a day when a PPL has to recover to an ILS/VOR/NDB flown via raw data, in which case the standard method of selecting a heading and monitoring the deviation bar would be useful to have in one's armoury. And also handy to be able to calculate drift and select a suitable heading for crosswind approaches and holds mentally.

What is the legal status of these Nav systems in PPL flying ?

Unless they are installed and listed in the Flight Manual, VFR only.

Yes, But, I'm sure you haven't done so by wafting from side to side chasing the magenta line. Rolling from side to side you will have a lot of sick passengers. In the cruise at 400 KTS drift is minor consideration but on approach at 140 -160 kts it is not minor. Pitching and rolling whilst chasing the indicated parameters is not the way to do it. Heading and time remains the way for a smooth ride.

While that may be true for aircraft with standard airworthiness certification it does not apply to experimentals in USA. The limitations on IFR/IMC operation of FAA registered experimental aircraft are only those included in the "operating limitations" that are part of the experimental airworthiness certification.

My experimental is IFR and coupled LPV approach capable but has no FAA approved Flight Manual.

One thing that has changed is the proliferation of controlled or prohibited airspace. Modern navigators are a very valuable aid to avoid busting airspace. Let’s not forget that every bust increases the pressure to further increase restrictions on light aviation.

So you may feel all self satisfied that you are eschewing modern navigation aids and doing it the traditional way, but when you get the call from the regulator you deserve what you get because you by choice did not use every navigation aid available.

The foundation principles of navigation haven’t change but how to apply them have. GPS navigators can only be properly used if those principles are understood, but just because you can do the old school map with a PLOG doesn’t mean you automatically are fully ready to properly use modern GPS navigators. I would suggest that as a general comment flight schools are not doing a very good job of preparing their students to succeed in the real world.