Pros - So many effects and amp models- that you will NEVER use them all. DEAD quiet, total quality all the way.
Cons - Cannot easily switch effects units in the one standard patching you may be in ... you must switch to another patch name. Not that big a deal. There IS a learning curve with it.
I had an anvil case with a Radial Tonebone Bassbone, a Korg Pitchblack tuner, a Boss Chorus, and a Digitech Bass Synth. I used a Power strip, and a 9v power supply with many output plugs, and a bunch of patch cables to connect all of them together. Even with the best cables and 1/4" phone jacks money can buy utilized, this SMALL pedal board was as much of a problem as dating a hot redhead. I had to frequently repair the connecting cables, even though none of them were ever touched.
It also weighed about 30 pounds with all the accessories in it.
The B-3 replaced all of them. In one much lighter unit. No more problems. And, the effects sound so much better, it's amazing. Especially the bass synth ones! All of what I need to play anywhere now resides in a Go-Pro camera case, and in a larger HP laptop bag that holds extension cables and a music book. All of it is half the size of my old Anvil, and a lot less weight.