I use both characters and I can say that approaching Mario and playin defensive against Mario is a pain. I still believe it's a doable match up if the ROB is on point, lol. Mario still doesn't have a very good neutral. And ROB still out ranges Mario in close combat (Nair Fair, Dtilt). When I fight Mario I fish for beep boop combos and I try to keep him the air. He's not difficult to juggle and even easier to keep offstage,
You can still out camp Mario if you're smart about it. I don't think ROB players should use Laser at all unless the opponent is pre-occupied and quite a distance from you anyway. Like being offstage or in the middle of an attack. Any intelligent player can react to laser's slow speed anyway so I don't find the cape that much of an issue since it's the same principle. Cape has actually been nerfed in frame data since Brawl so if you're facing a cape happy Mario, I find him easier to out camp. However, like said before, using gyromite is difficult in this match up because Gyro is one of the tools ROB has making him good. And Mario almost renders it useless.
I'll say 60:40 or 55:45 Mario.