I haven't tried it yet, I hate calculators. Your body usually lets you know what it likes (and doesn't like) pretty quick.

But I'm having some minor trouble getting the setup exactly right using measurements from the old bike as a starting point (that's prolly a mistake in itself, but don't hang me for it!). Different frame geometry means that if I get saddle position 'just right' my reach feels a little awkward (ie. a lot awkard after 4 hours in the saddle!). Or if I use a shorter stem and get everything feeling 'just right' then my knees touch the handle bars when I'm sprinting hard (Doh!). I've just put a new stem on that's 10mm longer, so that should bugger up the reach again

I was gonna use that calculator to see if I've made a fundamental bludner somewhere. What the heck, I'll give it a burl and let you know.