Thanks for your valuable feedback, Don.
I do have a bad habit unfortunately of playing too hard on the keys sometimes.
no excuse just because i'm a big guy with heavy hands, its something i have to keep aware of (to use a softer touch ... always). I'll get so excited when I play the harder rock 'n roll styles. Its something I want to correct.
It was only a temporary situation where I had the rental instrument to put through its paces and I figured better to find out now rather than later how durable the keys are.
I really appreciate your point, however, that when I get my brand new 770 to respect the instrument to the max. Absolutely. And along those lines, by the way, what's your opinion of paying for additional years of warranty beyond the first year (included)?