Oh dear god...nothing worse than making it look like...gasp a leisure centre....it's not an article that helps itself really.
I am a member of DL and joined on the back of one of those £14 fortnights (as it was back then...).
Whilst I do find it frustrating when they're on as the pool is over cramped and you occasionally have to wait for a particular piece of equipment, I can't say I have witnessed any terrible behaviour - or at least an uptick of terrible behaviour. I have to say that I do find the staff reluctant to challenge poor behaviour at my branch (kids pissing about on gym equipment etc) but as this happens in times when the deal isn't on, it can't be attributed to this.
Frankly, the cheaper gyms around here are better maintained and better equipped - but I'd miss the outdoor pool and padel courts which aren't available elsewhere, plus my PT is excellent.