Yeah - I actually have a Dell XPS 15 coming tomorrow (from Dell Outlet - so a 9560 7700HQ/16GB/512GB/4K for $1,149 and 16% cashback through ebates). Then going to decide which one to keep. I still want to keep the Mac, but I just don't know if I can justify over 2x the price for not much performance gain - basically just for OSX...
But yeah I know all about undervolting. I plan on doing that to the Dell XPS to see what type of results I get - maybe even repasting the Dell too. Then seeing which performs better for my use cases and deciding what to do. But now that you mention it, I might as well give it a go on the MBP too. If I remember and do this after work, I'll post what results I get.