Strength: a Spartan can lift around 3 ton if I remember correctly. The Nanosuit can lift the same (though not for the same amount of time!) Speed: Kelly could sprint up to 62 KPH The Nanosuit in the novels could get up to 300 kmh in bursts Those are the two factors that we're all debating usually. Then there's the factors that we can't really compare. Stealth: While the Spartan doesn't use any sort of cloaking device to conceal it. It can be extremely stealthy having infiltrated bases on numerous occasions without getting noticed. The Nanosuit on the other hand does use cloak as its ally. Becoming almost completely invisible for a time and can attack while stealthed. Training: The Spartans does have ridiculously amount of training AND augmentations we all know this. Though in the novels the kinda to drop like flies. The Nanosuit doesn't really need a all that training or drugs since it gives its host all the info they need while in the battlefield (UI in their eye, now how cool isn't that) I say if the both new that they had each other as targets and we're in a sort of general location. I think the wearer of the Nanosuit would notice the bulky Spartan before he notices him. That's all this comes down to. Who finds who first and since the Nanosuit can't be heard nor seen while stealthed and giving that it is light and very agile. I think the advantage goes to Nanosuit.