Has anyone switched to PC from Apple, using both?

I need to add a laptop to replace a dying 2006 imac. Would be used alongside 2009 i3 imac, ipads and airport extreme/express. I left windows camp in 2006, so don't know how smoothly it would run with my apple device. Has the booting speed been increased?

I guess the safe bet would be a Mac Book Pro, but i am facing some budgetary constraints, and have a harde time shelling that money if there are similar specd laps on the other side. Problem When I left Windows was worlds apart in ease of use and desing, has the gap ben narrowed? Is app integration more effortless/seamless?
Do you miss apple OS?

Sorry for the long post, and thanks as always for your insights

Maria