"Stand Alone" Boxes (Garmin 430) - Sole means of navigation - legal?

Probably this has been answered in this forum previously, but I can't find
it. Sorry.

I recently got into a friendly discussion with a knowledgable CFII who said
a Garmin 430 could not be legally used as "sole means of navigation".
Looking back, I think what he means is that "GPS" (even IFR certified units)
can not be used as sole means. Since the Garmin 430 contains not only TSO'd
GPS but also VOR, LOC, GS, etc., my position is that this unit (without any
other navigation equipment on board) is legal as a "stand alone" for use en
route, terminal, and approach . (I know charts are still necessary.)
Please advise.

The following came off the Garmin web site:
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GPS: TSO C129a, Class A1 (en route, terminal, and approach)

VOR: TSO C40c

LOC: TSO C36e

GS: TSO C34e

VHF COM: TSO C37d, Class 4 and 6 (transmit) and TSO C38d, Class C and E
(receiver)

The GNS 430 is the most versatile panel-mounted product GARMIN has produced
to date. It combines GPS navigation, VHF communication, and moving map
graphics on a big color display. This "all in one box" 12-channel unit
offers IFR GPS, ILS, VOR, LOC and glideslope capability in a single,
space-saving package

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