I've got one of each (the HD and the Ultralight) both with talon blades.
I don't know what the adjustable action is.
Al Mar makes exceptionally high quality fit and finish blades with
what is essentially out of date steel.
The AUS-8 is very sharp, but I imagine it will need to be touched up
somewhat more frequently.
I love mine, the HD is more of a safe queen,
I EDC the ultralight frequently.
Best letter opener that I own,
the HD is considerably more robust.
I probably won't buy another Al Mar
until they bring their steel up to date.
I like their stuff so much, I don't want
to find myself having to replace it all with
3V or whatever one day, so I'll just wait.
But that said I bought these two in just the past 90 days,
so there are certain models you just have to go ahead and get now.
I also own a SERE 2000 and it is a precision tank.