I tend to be a little more price sensitive when it comes to short overnights.
I generally stay at the Bath Road HI these days as it's <5 mins by bus from T3, and 10 mins from T5 if I walk up to the Compass Centre.
I've stayed at various LHR hotels, but do like something a bit more comfortable if I've time to enjoy it.
Getting there at 11pm and leaving at say 4am means I'm just going to (try to) sleep and take a shower. Paying £100+ for something fancy where I won't eat breakfast, dine, use the gym, spas, or really partake in any facilities isn't for me if I can get a £35 PI a few minutes further out, Moxy, or the Travelodge cheap near Hounslow etc. Got lounge access generally, so breakfast is taken care of there.
There are those here who wouldn't dream of paying less than £250/night for the Sofitel just so they can stroll to T5 in the morning and avoid local buses or the Hoppas.
There have been times when options aren't what I want to pay, I have remained in the terminal. JFK, SFO, TLL, LAX, SJU etc. I've done. Midnight or so arrivals, departures around 5-6am. Not comfortable, but £150-£200 in my pocket for what could be 4hrs after shuttles etc.
I would sleep in the back of my car if at LHR and it really wasn't worth paying for something.