I am using this android wallet now for a 2 months and it is surprisingly fast in transactions, almost instantly. That is also the question I have, how can it be so fast? Does it have special well-connected nodes in its list?

Now I also noticed how 'slow' my bitcoin core v0.9.1.0-g026a939-beta (64-bit) on my desktop pc (kubuntu) is when I send a transaction. It takes almost a minute before the transaction shows up on blockchain.info, where using the android wallet it shows up instantly. I already used addnode= command in the bitcoin.conf file to add five 'fallback' nodes from here https://en.bitcoin.it/wiki/Fallback_Nodes.