I can say that it is the 5th best Mario RPG and soon to be 6th best after I playe Mario & Luigi 3.
The problem with SMRPG is that the game feels like a RPG Square was making and then pasted a Mario theme over it. They throw in an awkward platforming element and some lame original characters...
So no one is of the obsessive RPG fan who buys RPGs of most niche variety?
My friend buys all these RPGs that I would otherwise never heard of, like Ar Tonelico. These RPGs are so niche that they are even niche in Japan.
RPGs for me have been a strange genre for me. I didn't really start getting into them until later in the SNES' lifespan with games like Breath of Fire and EarthBound though I never really got into the Square RPGs at the time. So one of things I wanted a PS1 for was to finally get a real chance...