This tread has me thinking.....which always hurts.
I've always had good luck with syn oils in vehicles but tried them for the first time in my 2010 SG at 4000 miles.
I Went with Mobil 1 VT 20-50 in the crank case and noticed immediately that valve train noise was quieter up to 3000 rpm, after that, much louder. Since I often shift in the middle of the torque curve (3500 rpm), I cringe when I hear all the rattle.
At 4200 miles I changed the tranny oil with the VT Redline with the supposed "shock proof" for all the great smoothness it had to offer. BS IMO. No difference, For me in many respects it's worse after a few hundred miles and especially when it gets hot. But it looks cool (peto bismol).
At 4500 miles I put in the redline primary oil for all the same reasons. Made sure my clutch is adjusted correctly and once again... no difference from the HD option.
After my experience I'm going away from the "high priced spread" and changing back to the convenional HD oil and change it often.
We all want to do the best for our investgestment, I've just not seen the justification for the additional $$$.