Question for frequent users of lhr clubhouse

We're off to Dubai in Sept - huge excitement. At last we'll be able to experience the LHR clubhouse that I've read so many good reports about. Obviously it's a night flight (22.05). Is there a 'best' time to get to the clubhouse? Does it get ridiculously busy at certain times or is it fairly free flowing? Wondering if arriving at 5pm would be too early for a 10pm flight ...? Views from those in the know will be appreciated 
