no, i haven't tried lexapro, but have you not seen any results so far? you'd be able to notice if it were working for you. also you might need a higher dose depending on your anxiety level.
plus, they say it can take up to 6-8 weeks for the full affects, i'd give it another week.
but yeah, deffinately talk to your doc! but tapering off one and gradually starting the other is how most docs do it. beware of the withdrawl affects!
but with me, it took about 2 weeks to start to see results from the paxil
sorry i can't answer all your questions