Oh goody goody. I get to be a geek for a few minutes.
Spartan II: Hands down. Here's a some food for thought.
The circuits in the MJOLNIR Armor are *thought* responsive.
A Spartan THINKS about what and how he wants to move next and he does. Near instantaneously.
All Spartans are trained to be the best of the best of the best. (Sir!) Lol
Hydrostatic Gel vs. Semi-organic nanoweave fiber technology.
Tough to to say honestly.
But how about this.
Lets consider how the armor ITSELF is a HUGE factor.
If MJOLNIRs Shield goes down, it still has a composite armor that at least deflects bullets and will probably hurt if u punched it.
if a Nanosuit gets disabled...its just a guy in a gimp outfit...
Spartans are biologically augmented and enhanced Supersoldiers. Enhanced skelature. Enhanced muscles. Enhanced hearing. Brain function. And btw they are like 7 feet tall.
For those that are saying, "the Nanosuit has stealth".
Ok...Spartans have motion tracksers...and any battle-hardened Spartan knows what crappy looking Active Camo looks like.
And a Sparran would hear someone sneaking up behind them...
Did i mention Spartan-IIs have SPI armor? Semi-Powered Infiltration Armor. Aka cloaking ability.
Spartan vs. Nanosuit guy...
Spartan wins 9 out of 10 times.
(Ive read all the Halo books, seen Halo Legends, played all 6 games im SO ready to geek spaz out.on someone)
And yet you die from stupid gun in game

. Also u cant hear someone sneaking in nanosuit, because footsteps sound is not present during cloak mode.