The XLS is has a more natural frequency response while the TLII has a bit of rise in the high treble- supposedly to allow vocalist and lead acoustic instruments to cut better through the mix. All C414's are generally considered on the brighter side of transparent, so I felt I didn't need the extra zing. YMMV. I love my XLS- there are probably better 1st choices for pure vocal tracks, but as an all around mic- you could do A LOT worse than a 414.
