I always replied to the citizenship invite email. I was following for some time this forum, for last one moth I was seeing the decision is made after 4 or 5 months after the exam. any how suggest to do a analysis before sending an email.
Im sheduled for oath on 23rd as well. No invitation yet. Seems like 23rd is a in person oath. I guess they will have a interview and give the oath on same day.