I certainly don't want to take the entire GPS out of the aircraft and load it into a docking station every month.
Suprisingly for an IFR approved GPS, its database does not contain any SIDs/STARs, which precludes its legal use for such procedures, but bizzarely the database does appear to contain all their individual waypoints which can easily be manually inserted into the flight plan.
It is a mystery why Honeywell introduced that limitation, but it is not currently operationally relevant, not least because most if not all airports that publish all-RNAV terminal procedures do not operate them and use radar vectoring. The KLN94 does have analog vertical (VNAV) outputs (from its installation manual: pic1 pic2) and obviously the intention was to deliver a "GPS derived glideslope" capability, but Honeywell's GA division collapsed around 2000 and they stopped product development other than trivial fixes.
If you are one of the many pilots who have used the KLN-89B, then you already know much of the KLN-94's operation.
The most obvious improvement the KLN-94 offers is the color display / moving map.
To quote from my , “Whenever a runway or heliport has two or more RNAV approaches, a single alpha character differentiates them.
The first GPS approach charted to a runway is labeled “Z,” and subsequent approaches are assigned other letters, moving backward through the alphabet.The rest of their 206s are round gauge airplanes with the KLN 94.In these latter aircraft, there’s a potentially deadly issue with flying RNAV (GPS) Y and Z approaches, so he’d been thinking of calling me to discuss it.Before an IFR GPS can be used for flying GPS/RNAV approaches (example) it needs to be approved for this purpose, by the aircraft's certification authority.Merely installing an IFR GPS, with the required separate annunciators, is not enough.I might suggest checking the manufacturer's web-site to see if A) They have the hardware available that you need to do the updates, and B) they're still providing updates for it.