I use the Apex with both the PSR2000 on top and a Roland VR-760 on the bottom - no problems using the standard tribars. (the 760 is a pretty hefty 76-key board too).

I have an X stand and a table-type. I always go back to the Apex because it's easy to use and transport. Lately I have only been using one keyboard and putting my laptop on the upper level - works great.