For a solo performer who needs to travel as light as possible, and requires quick setup/breakdown, the advantage of a 'built in' vocalizer is obvious, as in addition to transporting & seting up the external vocalizer unit itself, there's the mounting rack/bag, wires, additional wall wart/AC plug, and possibly even an external mixer for phantom power, etc to consider.

Another IMPORTANT (yet not mentioned here before) advantage to a 'built in to the keyboard' type vocalizer is that vocalizer settings can be stored & called up along with a specific song in the keyboard's 'registration memory'. A song may consist of 4-5 different vocal harmony changes, so it's a lot more convenient to have these settings stored along with all the other reg settings (style selection, instrument voice setups, etc) than having to store, call up, and trigger them separately via a 3rd party unit (Digitech) and trigger the changes via another footswitch pedal as well. It's much more convenient to store/call up EVERYTHING in one place and trigger everything via a 'single' footswitch.

I find the PSR2000 built in vocalizer provides decent sound as long as the harmonies are kept in the background, which is fine with me, because I don't want to be upstaged. The Tyros' built in vocalizer sound quality is significantly better, and imho, almost on par with the Digitech "Vocalist Workstation EX", but of course, not as good as the substantially more expensive & costly TC Helicon 'Voice Prism'. I recently sold my Digitech "Vocalist Workstation EX" and now utilize the Tyros 'built in' vocalizer exclusively for live performance. Still, I may consider purchasing the TC Helicon "Voice Prism plus" for studio work when my finances permit.

Scott