Having come from a big church and currently attending a big church...i hear the same primary complaint from people who visit, mainly "This church is TOO big." However, I don't think the complaint is directed at the size of the church. What i think the real complaint is "I don't feel like i fit in." I feel that this complaint is easily to address for the church.
If you currently attend a big church:
-look at who is "hugging the wall" in the foyer. These people are probably new to the church and a bit taken back by its size. Greeting them helps connect them to the church and makes them feel involved.
-Similarly, look for those wondering the foyer/sitting alone as they can also be new people.
Basically in case those points didn't do it for you...LOOK FOR NEW FACES! Yes most likely the greeting team welcomed them, but real conversation starts with us stepping out of our comfort zones and saying hello.