Upgrading Left side slung bottle regulator advice please

[Scared Silly]

My suggestion is always to buy regs all of one brand. If your primary first or second dies for some reason then the backup is just like it and should breath the same. Further when servicing it is one stop at a shop. If you are happy with the aqualung buy another first/second and do not look back.

 

[Nemrod]

Just get another Core. It is an excellent regulator.

N

 

[mdwalter]

The other 2 considerations I have is
1. ... Does it make more sense to make the new Regulator my primary and put my AL core on the Pony (which would get almost no use except practicing with it)?

2. Do people have qualms about using the first stage and button gauge and 40 inch hose I already have and putting a different 2nd stage on it? ... If so is the button gauge transferable to one of the ports on the new 1st stage?

1) Not really, since your current primary is only 2 years old and you like it, keep using it.
2) I have no qualms about that. Just buy yourself a new 2nd stage, unscrew the terrible old one and throw it away so nobody else has to inherit all its problems, then screw on your shiny new one and enjoy. No need to invest in a new 1st stage, hoses and gauge unless any of those is giving you problems.