I've had these two motherboards, for some time now:
ASUS - "Rampage III Extreme (x58)" & "Sabertooth (z77)"
My primary computer recently failed(*) and I felt rather than repairing(*) it, replacing it would be the better solution. Meaning, in the meantime, I will breath life into one of my previous rigs; until a viable replacement becomes available.
But, which is better?
"Diego" - z77 + i7-3770k (& Phantek PH-TC14PE), w/ (4× 'AX3U2400W8G11-DMV') ADATA 32GB PC3-19200 CS:11(*) - in, Enermax Ostrog Adv. (Rd)
"Larry 2.0" - x58 + i7-990x, w/ (6× 'CMT6GX3M3A2000C8') Corsair 12GB PC3-16000 CS:8(*) - in, Deepcool Genome II (Grn)
...
Which between the two is the superior build? ... which one will be worth it to 'overhaul' as a replacement build until components better suited for the NewRelease(*) Chipset/Socket/etc. -- as a fair compromise/alternative to utilize until then... until then.
(The x58RIIIE also only has 50% RAM being utilized ... I cannot for the life of me find greater than 24@1600DDR3-TriChannel modules... !but! am willing to switch out its RAM, if it means improving.)

Thanks.

My EVGA Classified3 x58 w3680 hexcore xeon at 4.2ghz with a GTX1080 plays anything and everything I throw at it at ultra settings.
I had a single GTX1080Ti and GTX980Ti in SLI on that board and it never lets me down.
Running 2 x 8gb Gskil Sniper 1866 memory 9 10 9 25 2
Have 2 EVGA FTW3 with the xeon x5660 at 4.1 or so and had my GTX980Ti and 1080 on those boards and they play everything too.
 

Apparently (I found humor in it) Linus has put up a "tutorial" (sponsored by Intel) for the new i9 series. ... is it even worth it for me to $try$ with my old rigs? ... iGuess without a budget heighending the $3,000.00 margin, I'd be better off "frankensteininf" either one of these 2, and just slap on a GTX1080(*) ... or something.
>.<

I'd rebuild z77, and sell your x58 mobo while it still has insane value

For either the two of these particular, I'm just wanting to get the most out of the hardware which I've had to make due for the time being. As the primary use of my primary computer is heavily orientated to that of server work and graphics-rendering (excluding "bigPicture", they all have the entertainment / server accessibility{*} aspect in mind --*Adobe's, SpreadSheets, Blender, things of that sort).
...
Ultimately I'm attempting at having a few at my disposal, to utilize and navigate/coordinate a small number of persons with whom will work{*}.
- the easier/faster it/they are for accessibility/etc., the better.

**more'est,Important-est,,ofAll: as an Enthusiast,, aren't you curious which may outperform?** :P