Only been once. On a Saturday.
Bus to Wimbledon, Tram to the Croydon.
Walk round shop.
Pick stuff (big flat desk and legs, wheely chair), write down part numbers/warehouse locations.
Go find stuff in warehouse, not too tricky but several bits in the wrong place.
Through the checkout and straight over to the delivery desk.
£20 to have it all delivered the next day.
Walk out of store with just a receipt.
Hop back on the tram to Wimbledon, bus home and stopped off for a pint.
No traffic nightmare, relatively hassle free, and delivered first thing Monday morning. Whole thing done in two hours which, if attempted in a car at that time of day, we'd probably still be sitting in a queue of traffic on the A23 not having even got to the store yet.