Reviewing my post with the link for the L2 quotes, I may not have been as clear as I could have been.

The data for the Level 2 (MM bid and ask) are Real-Time but the actual last trade (price) data quote is delayed.

When a MM changes their interest on the bid or ask, you'll see it (also, this site 'self-refreshes' very often) so you should not miss much.

The one drawback I see is you don't get the trade history like at the other site (where moo gets his daily T+S from).

But when I look for the best price I can get before I log on to my broker, this site is great.