Deathstroke's weapons and technologies are far too advanced for Guts to really compete against. Give them both equivalent weapons and Deathstroke loses.
His speed is highly enhanced in that armor, and he has some amazing damage soak in it. For example there is the case where he destroyed the thunder apparition of the emperor, and his fight with several of the emperor's top sorcerors where he showed agility in the berserker armor that was about spiderman level at least.
That was with Zodd's help, he had to fly through that spot in his head (and Ganishka thought he was invincible so he was just staying in one position and not attempting to dodge).