I haven't tried top mounted yet when it comes to 60%. It's hard to say which I'd prefer more, though I do really like the compatibility and solidness of the one piece tray style. In my experience with plates that are "suspended" from being top-mounted, both in vintage designs and customs, there's a bit more springiness to the typing feel. A bit more flex because of there being that floating area of plate around the mounting points.
I notice, with my Orion v2, now using carbon fiber for the plate material, but with stainless steel as well, that you can feel the energy of the bottoming out being transferred through the plate. Like I can feel vibrations in my left hand through the keys when I'm using my right for typing and vise versa.
With the tray-mounted version, the case pretty much deadens all that, especially if you use something like a shelf liner mat or sorbothane.
I haven't dampened my Orion though, mainly because Alps SKCM Blue would become pretty muted. I'm sure if there was pressure beneath the PCB, it would deaden those vibrations.
It's actually something I've seen a lot of vintage top-mounted Alps boards do. There's usually some kind of dampening device in between the PCB and case supporting it. Usually some kind of rubber pad.
It does kind of feel nice though.
With tray-mounted, it feels like you're typing on a brick, haha. Which can be good for certain things, like linears. Very solid feel there.
