We need to install some whole house humidification (lots of static electricity and getting a piano). Our HVAC contractor has recommended an Aprilaire 800 due to configuration of our air handler and ductwork and house size. Anyone have experience (good or bad) with this unit? Thanks.

Installed properly and maintained they are great units.
I’ve had one in my home for 10 years.

We just had a model 800 steam humidifier installed in our house (along with new HVAC system) about 2 months ago.
So far, it is delightful, and worth every penny.
Granted, we haven't had typical winter weather this year...but the humidity has stayed rock-solid at around 40%.

I installed a 400 this winter and love it.