I've used both.
The Hawke has a very 'warm' image, excellent at low power, Great at middle but soft, very soft at high zoom.
The Opticron has a very neutral colour to it. What you see with the eye is what you see through the scope. Excellent all the way to the end of the zoom, and the dual focus is a dream to use. Very smooth, very precise, lovely if you have gloves on.
Weight wise, the Opticron is a feather, throw it on a mule pack and you can forget at times you are carrying it. The Hawke is hefty but like my ol 85ED? Is going to take a shed load of abuse and keep rocking.
All in all? Go with the Opticron now that they are water \fog proof.