Also had bad traffic getting into T3 on Saturday August 26th, and that was at 7.30am.
Fortunately the mytaxi driver (hat-tip to Raffles) was adept at cutting in and we were going to drop-off rather than the car parks, which is where the problem appeared to be, so we were ok Jack, but others must have been queuing for ages.
Edit: and it might have just been because it was a bank holiday weekend, but it was pretty slow.