I love my Corona Excalibur. Wouldn't trade it for
anything. In fact, I love it so much, I carry 6 of 'em.
Incidentally, my fav 1.5" brush is the Corona Ryan - the bristles are the finest chinex I've ever used, probably half the diameter of the bristles in the 2.5".
And FYI, Chinex is useable for both oil and water based coatings. I have been told that Chinex is a white china bristle which has been treated or coated with some kind of DuPont chemical in order to create a whole new filament type. Not too sure about that, but all I know is they are an absolute pleasure to work with, using every single coating I've ever tried them with.