http://www.pentaxforums.com/forums/172-pentax-k-3/242556-k-3-delay-when-using-flash.html
Some K-3 users reported that the delay was particularly long, noticeably much longer than that of the K-5, which was not that noticeable.
Another thread at the Taiwanese PFC Pentax forum also states the same thing:
http://www.pentaxfans.net/
