Agassi is nowhere close to Janowicz in terms of variety. Janowicz doesn't even need to run too much. Agassi benefitted from better fitness and some weak hard court opponents.
Janowicz is better than Agassi, you heard it here first.
For what it's worth, even though I absolutely hate Raonic's game, I think he will serve-bot his way to slams in future. He's good for a R4 these days, and just needs a few good serving days to edge out some tie-breaks and take a slam. Plus, his game is based on standing still and serving, so he will not decline quickly.