Naturally, if you are an arranger player only...it would be no contest...
You would not paint your house with a toothbrush..or brush your teeth with a paint brush...different purposes.

The PC80 would shine on stage if you wanted to play over sequences or MP3 tracks using superior sounds to what you are using on your arranger..like NI B4..

With a single connection of a USB cable to your laptop..the PC80 has the power, the audio interface with monitoring without latency..and the outputs to stereo speakers and a sub connection..

How many connections would it take for an arranger keyboard to do the same job?

The best purpose is in the studio..easy and fast access to MixCraft, and PC80 softsynth...Win ..Win..