Just seen that post from Havick..
First time I landed at ORD. Night time, raining and when we switched to ground it was so congested (taxiways) we were advised "If you can see a way through, go for it!" I'm not joking.
Go the LHR, or anywhere in the LTMA, the controllers speak slowly and clearly to crew that clearly are unfamiliar with the airspace, taxiways and language. And guess what...... less blocked frequencies due to read backs required. How simple is that.