Answer to your question:
According to accounts from friends and family, most people don't really notice a significant benefit. However the word ECO-PRO was not designed to be a take on hybrid, so it serves its intended design well.
This is additional to your question, but to expand on your question. Does the benefit that most receive from engaging the ECO-PRO profile have any negative effects on the powertrain and long-time maintenance costs on these vehicles, such as more starter cycling and other various components.
BMW and Mercedes Build Beta Products!
Lexus build Release Candidate Products!
Why does this matter?
CAUSE EVERY TIME someone says Lexus has better build quality, one should consider what Toyota their Lexus Engine and chassis platform comes out of and how long that part has been tested in the real world!