Hear the Breakdown...
Strength: Even. I wouldn't put either one above 5tons. And their striking damages are about the same.
Durability: Slade> Midnighter. While the both of them are tough as hell Slade has two decent advantages over Midnighter. One he has pretty durable armour the same one that took the tank round to the chest. As well as survived a grenade explosion at point blank. Wally described beating on Slade to be similar to hitting a brick wall. And while it isn't too battle powerful Slade does still possess a haling factor.
reflexes: Slade=Midnighter. I've seen Slade,while sitting down get shot at by three guys with machine guns, nd before the bullets it he umps up out through the sunroof and decapitates them in one swing. And I've also seen midnighter kick a shell back at a tank as well as yawning while dodging gunfire. It is really hard to say anyone is faster int hs department.
Hand to Hand: Slade=Midnighter. I imagine that without their powers both men would probably still be well, trained though not exceptional martial artists. While he could goonsweep like madman Midnighter deosn't do as well against names. Slade has had trouble with really good martial artists before.
Weapons: Slade>Midnighter. Slades standdard loadout includes his sword, an energy staff, a submachine gun and wrist mounted grenades. Midnighter uses a staff and some throwing stars. hile Midnighter noally does well agianst theses sorts f weapons in the hands of someone like Slade they are far moe dngerous.
over all: Deathstroke 6/10. Barely. I think his greater durablity will tell allowing him to eek out a W after along life threating fight.