in my experience, slow pace offence tends to work good for team with offensive flow advantage.
if my shooting is by far better then my opponent's D, i would play fast, since i would get many high % shots
if not, but i have better offensive flow, i would slow it down, using my good passing to get better looks
slow pace in case you have low flow will result in many shot clock violations, since you players are well guarded and having hard time getting their own shots, plus, no one is there to set them up with a pass
but that is just my own opinion