Alice for me. I felt a better connection with her than Giulia which, for me at least, enhances the experience. She also offers anal now if that's your thing.
There's quite a difference in appearance if that matters to you, but that's fairly clear from their profiles/reviews.
Of course if price is critical Alice is (now) a tenner more for the hour, and £30 more for the half hour. Giulia's 30 minute rate is looking like pretty good value.