Wow, dude! That's about a 33% discount!
Fantastic deal!
Yes, I have a R500c and can only
dream of getting a Studio 40 to run into it. Yes, Studio fx send to 500 fx return would get you just a small notch down from the Stage 800!!
Worth it compared to the B3n? Do you
really like getting
lots of different sounds? By
lots of different amps,
lots of different cabs,
lots of different effects? Is variety a spice of your life? Would remote control by phone, or tablet, app be of use to you? I have no qualms answering "YES"! Especially at that price!! But, that's just me. I dunno 'bout you. Do you?
Have you perused the
Rumble Stage & Studio manual to see if it interests you? That, and much more info, is also linked on the wiki page in my signature.
Good luck, either way!