It feels weird, at first - almost like you are wearing a thin cap. However, that feeling goes away rather quickly. The only time I ever feel any tightness, is the first day of a rebond, and it’s super minor.
I’ve been using lace systems for 3 years. The first time I had a system attached it felt a bit strange - similar to what wearing rubber gloves feels like on your hands (if that makes sense). The hairdresser assured me that would pass and it did after a few hours.
the only other times it’s felt a bit itchy have been if I used too much glue (I used to glue all over and now use minimal glue and mostly tape) or if i leave it too long to take off and maintain (usually around two weeks).
99.99% of the time you don’t feel anything. It’s like wearing a hat, eventually you get used to the feeling and it feels like it isn’t even there.