I can assure you that most, full-time, gigging musicians would NOT embrace a 40-plus pound arranger keyboard. Additionally, they would NOT embrace fully weighted, hammer action keys. Having spent 50 years on stage, the first 20 performing with a guitar, and the final 30 years with an arranger keyboard, your body quickly rebels when you try hefting all that gear on stage, then tearing it down at the end of the night. As for the keys, well, at the end of a 4 hour performance, 7 days a week, tell me how your hands feel. I did a grand piano job using a Steinway Grand, which sounded incredible. At the end of the night, I was barely able to hold my car keys.
I know a half dozen Peabody Institute trained pianist, all of which switched to performing with an arranger keyboard. Each and every one of them loves the lightweight keys of their PSR and Tyros keyboards. They no longer have to soak their hands in hot water when they get home from a 4hour job.
Now, there was a time when I too performed with two keyboards, one a 51-pound PSR-5700, which had the absolute best piano and vibes sounds of any keyboard ever. It sat on the bottom tier of a three tier stand. On the second tier, I had a PSR-500, while the top tier held my mixer and vocal processor. My PA back then consisted of a 35-pound Peavey 600 powered mixer, and a pair of Peavey SP5 15-inch passive speakers mounted on heavy-duty poles. My set up time took about 40 minutes or more and three trips to the van with a refrigerator dolly loaded to capacity.
The system sounded great, weighed hundreds of pounds, and when my popularity increased as a result of some very aggressive self promotion, I soon found that I was having a great deal of physical difficulty setting up and tearing down two to three times a day, seven days a week. I had to make some drastic changes, but still retain the sound quality. This required a lot of research on my part.
My first move was to find a lightweight keyboard stand that would set up in seconds. I still needed two tiers, but the top tier was reserved for a custom console that I designed. The console was initially constructed of lexan, but I later redid it in 1/8-inch thick aluminum. The lexan model developed some stress cracks after a few months of use. The console held all the power supplies, vocal processor, and small PC that contained my lyrics and midi files. Additionally, the front of the console became a lighted sign, while on the back of the console, a strip light provided a soft light over the entire keyboard for when I performed in darkened rooms. It also held my surge protector which has a ground fault indicator. Everything remains plugged in at one end, and connected to the surge protector. Only the plugs that go into the keyboard were unplugged during teardown. This alone reduced setup time by a huge margin.
I then moved to a new, lighter weight arranger keyboard with a built in vocal processor - the PSR-2000. I quickly realized that the 2000s piano sounds were not nearly as good as the 7500, but with a bit of tweaking and tuning, I could get a more robust sound and the audiences really didn't know the difference. Now I had a 23-pound arranger keyboard instead of packing around that 51-pound monster.
The next step was to lighten the sound system, which I did by switching from Peavey to a pair pf Barbetta Sona 32SCs which only weighed 32 pounds each, instead of the 72-pounds that the Peavies weighed. Those Barbettas were later replaced with the Bose L1-PAS, which was later replaced with the 23-pound Bose L1 Compacts.
Just prior to my retirement, I was able to set up my entire rig in just under 7 minutes, which made life a lot easier as my health began to fail. My audiences had no idea of my health issues, and they were shocked when I announced my retirement.
As for the risk of performing with a single keyboard, in more than 30 years of owning arranger keyboards and thousands of performances, I never experienced a complete keyboard failure. If I had, I would have been able to get through the job using my PC and midi files, then when I got home, I had a fully prepared spare keyboard ready to go to work with. This is a must for anyone that is a full time entertainer and makes their living in this industry.
Good luck,
Gary