So, got the Sig Pros today.
Early impression easily in favour of the T5p for metal particularly, but more time needed.
So far tracks I have compared:
Tool - Forty Six & 2: The intro has some great delicate drumming from Danny Carey with a variety of splash cymbals, occasionally strikes them from underneath also. I think the Sig Pros imaged these better and have a wider soundstage to place instruments in, and so they sounded more well articulated there. Besides that preferred the T5p for this track.
Pantera - 13 Steps To Nowhere, Throes of Rejection: Two tracks I like to listen to to zero in on drum sounds in their respective intros (also bass guitar sound in the latter). T5p easily outgoing the Sig Pros to my ears here, with a much tighter sound.
Guns N Roses - Right Next Door to Hell: Primarily listening to the thundering bass line in the intro, but also listening for the characteristic sound of distortion of the Gibson guitars/Marshall amps (I formerly owned a Marshall Stack and Les Paul, now have a more modest guitar set up since I was never good enough to deserve the LP/Marshall pairing). Again easily prefer the T5p.
In all tracks prefer how guitars sound on the T5p, more forward and aggressive (as they should be), guitars on the Sig Pro sound polite and lack bite in comparison.
Lots more listening to do obviously, and the Sig Pros may improve of course (if you believe in burn-in that is, certainly I believe in brain burn-in, so as I get more acclimatised to how the Sig Pro present sound they may go up in my estimation).
Hope this helps, perhaps the OP has some reference tracks in mind that I could A/B also?
Well, I mostly listen to metallica. If you could A/B "The day that never comes" (or "the unforgiven" if you don't have it), "Eye of the beholder", and "The call of Ktulu" that would help a lot! Thanks for the help :)