I curently have a Quicksilver 27P I was going to have labbed.
Would I notice much difference if I purchased a Mirage Plus 27P. I understand the Quicksilver is a little more stiff?

I would reconsider lab finishing your prop. If needed, a reconditioning should be all it needs. Typically you won't see much of a speed gain from a standard Mirage or the older Quicksilver props after lab finishing.

A Mirage Plus 27 will run about 200 rpm less than your Quicksilver.

Why is that? Same speed and less RPM?

Looks likes it time to put the old quicksilver back on Ebay

You can gain small amounts from Labbing the Q.S. props. You need to change the Blade area and the geometry and the rewards very.

As far as the standard Mirage, we find big gains if the application has good top speed numbers with rev limiter R's and high slip % by turning them into Plus's.