Completely disagree with some of these posters, but then I'm a regular user of the Picadilly Line to Earl's Court, the stop before Gloucester road. Sometimes it's closed so I'm forced on to the Heathrow Express or the Elizabeth Line and have to change at Paddington.

Getting on to any of these at LHR is easy. The Piccadilly Line is closer at T2 and further at T3, and not much different at T5. There are no steps for luggage etc. there. When arriving at Gloucester Road, whether by Piccadilly Line straight from LHR, or by Circle Line from Paddington, there are steps. Plus, the change at Paddington uses very narrow passages and is mega crowded, even out of rush hour. And it has steps both up and down, unless you go out of the station and across a main road when you can miss out one set of steps. Finally, in most circumstances, the trip via Paddington will take longer, and often significantly longer.

If you are travelling during rush hour, the Piccadilly Line will get crowded as you approach central London, but you will have a seat and will have stowed your luggage when you get on the empty train at LHR. If you change at Paddington at those hours, the Circle Line will be crowded and you may struggle to get on with big bags.

So, to me, there are only three sensible choices. 1.Taxi/Uber straight from LHR (which, in rush hour may take longer). 2.Heathrow Express/Elizabeth Line from LHR and Taxi/Uber from Paddington to Gloucester Road. 3.Or the Piccadilly Line. To my mind, 3 is the most reliable, 1. is the most comfortable and 2. is just a bad choice.