I don't agree. Those quotes are provided by HFTs and automated market makers. What that means is that they are a complete illusion. On top of a massive speed advantage these guys have special order types that basically mean they can flash quotes thousands of times per second while having order types that ensure their orders don't get filled. Throw in dark pools and Level II stopped being useful somewhere around 2008 is my guess.BTW, do you have Level II quotes?
It is absolutely essential to have that when trading.
Not being able to see the order queue incl. the individual order sizes is like shooting blind.
Real time quotes I agree with - although that term is not very accurate given the huge delay between what we see and where the action really is going down in the first few hundred microseconds.