not beertracker, but I've used a few sacks of Optic before (and I've used TF MO as my ale base malt >4 yrs). To me, Optic lends a little more candy-like maltiness and slightly less bready/biscuity than MO. Those were the only detectable differences I had. I didn't like the candyness in the malt as much so I went back to my old standby MO.
Would be interested to hear beertracker's take as well.
I'm experimenting with Halcyon for the first time on Monday morning. Looking forward to it!