I don't detect any particular lag when posting or making a thread; not more than what I would attribute to usual www and network latencies, and my own ISP's latency. Only noticeable lag I detect with LQ is when searching/reading zero-reply forums -- the server(s) take a moment to conjure up the zero-reply thread list -- and I've always figured that was understandable. It isn't long, maybe a few seconds.
Something I have noticed an increase in, which I used to believe affected primarily only
moi, is accidental double-posts. I'm not sure what causes them (and that may be a subject for another thread) but if there
were anything inducing a lag as described by onebuck, then perhaps the double-posts could be related too....? For the record, I am no longer plagued by double-posts (knocking on some wood).