Hi, is there anybody there with good experience of acoustic pianos who could comment on how good string resonance is on the latest yamahas (CLP 380, CVP 405-409) compared to the Roalnds?
I have tried both and have noticed the Yamahas do seem slightly less realistic in that there are combinations which don't seem to resonate as I'd expect (e.g. try holding down a cluster in the top of the keyboards and the virtual strings don't always resonate with the bass as I'd expect). But I'd need to spend a couple of hours in the shop to get a good idea! Any comments?

On the HP-207 anyway, you can adjust this feature and turn the amount of string resonance up or down (default is in the middle). It's a pretty subtle effect and not always noticible, especially if you're using the damper pedal anyway. Still it's nice that Roland puts it into the mid-range HP-203 as well as their flagship.

I can't really comment on Roland vs. Yamaha accuracy. I haven't spent enough time with a CP-380 to be very familiar with how it manages the effect.

Nuances as this are often revealed by concentrated play over an hour or two. Find a shop that will let you have at it with headphones and put them through their paces. Also look for the instrument that allows you to express yourself the best. Often times folks are listen for with the instrument will do instead of listening for what the instrument will allow them to do.

I like the idea of listening to what the instrument will allow me to do rather than what it will do...

Has anyone ever seen a full review (or even technical specification) for the string resonance? The reviews I have seen have been pretty bad, not much more than "it's great, wow, and it does string resonance, groovy", I'd like to see something a bit more objective"

Here's what Roland's web site says:
"String Resonance accurately reproduces the subtle and varied sympathetic string vibration caused on an acoustic piano when a key is pressed while other keys are already being held down."

There are 10 available levels of intensity which can be selected.

In essence, it does exactly the same thing as damper resonance, but only for the strings which are currently depressed. Pressing the damper pedal minimizes the effect, since those strings (and others) are free to resonante anyway.