Are you asking re NYC specifically? I have only had negative experiences at Enterprise in NYC (lovely staff but always garbage options, and inability/refusal to upgrade even if they are missing the class you reserved) and only positive ones at National (always given something very new, and twice upgraded to very nice vehicles). The National garage on 57th, shared with Alamo, is significantly larger than the ones at the Enterprise locations I have been to, but it all depends on availability/randomness. So who knows