Amplifier with higher OIP3/IIP3 the more linear it is?

Probably. In general. Maybe.

Equate IP3 with linearity, and see manufacturers start making crappy amplifiers with great IP3 specs.

not sure what tim is trying to say ... but yes OIP3 is the accepted linearity spec for RF amps. drawing conclusions about spectral regrowth with digital signals can be a challenge sometimes, but for sine signals it is a direct correlation to linearity.

i've experienced vendors who use OIP3 in non 50 ohm systems as an attempt to make their spec's look better. a/d drive amps are a particular example.

jdc

I meant "Apply that specification outside of radio (where it makes sense)" etc., etc.

For a while Motorola was specifying their CATV amps in some unusual way

-- either 3IM with multiple input tones, or 5IM, I can't remember which. And I don't know if they still do, or if anyone cares in this digital age.