Is gcin supposed to introduce a noticeable delay?

[Bruno Wolff III]

I had an issue with gcin running when it input methods were supposed
to be turned off (if I can duplicate that part of the problem I'll file
a bug report on it) and it was causing a noticeable lag between when I would
hit a key and when the character would show up. Is it normal for it to have
a delay on the order of a tenth of a second when using gcin? If not I'll
retest it and also make a report about that. I suspect the behavior is
necessary in order for key combinations to work, but am not sure.