Any opinions on traveling T3 to T2? I did it once with a 2 hour connection to T1 and ended up waiting around for 1-1/2 hours. Next time, tried it with a 1 hour 20 minute connection to T2. Naturally, UA arrived 1 hour late. Missed my connection, which was NOT on a partner carrier and -- worse -- on a separate ticket. I had to plead just to get on the next flight, because the rules of the ticket I bought didn't allow changes. Oh yeah, they cancelled my return too, but that's a different story.

So, I'd like to try the 1 hour 20 minute connection again but am nervous about it now. What do the LHR experts here think?

If I do miss my connection due to UA's late arrival, what's my best course of action at that point? Will UA help this 1K? I'd hate to wait 8 hours again at LHR for the next flight onward and a day-trip into London after not sleeping all night just isn't much fun.