Manley Snapper Triode Switch/600 ohm switchable?

Hi Guys - Im curious if someone can explain a couple of things...

I get that the newer Snappers have a Triode switch for a smooth/relaxed vibe & a punchier/ tight feel....

so the earlier Snappers are just the smooth/relaxed ....new : Triode switch(Ultra linear) is the punchier option with Triode switch...? 

Also ...my speakers are Tekton Encores 4 or 8 Ohm impedance. Snappers have this XLR : 15 Kohm or 600 ohm Switchable....does this benefit me anyway? 

Thanks!