I prefer the screen, but I don’t have a problem with face-to-face. When it is a confession that requires more of a conversation — not all confessions lend themselves to “be brief, be bold, be gone” — I actually prefer face-to-face. For one thing, it is much easier for me to sit, than to kneel.
Once I had to make a deeply troubled confession (troubled on account of my life circumstances at the time, more than the sins themselves, though all sins should be “troublesome”) and I simply could not kneel, so I asked the priest if I could reach around and get the folding chair I saw sitting right by him. He was happy to allow this.