Haven't used the new one (the Circle Line has improved the reliability of the journey over to Kings Cross, so I tend to use it now), but always found the old one pretty poor for queues on exit at busy times. It's particularly annoying to jump in a taxi, and then have 5-10 minutes of the fare increasing before you've even left the rank! Then you made it out to Praed Street, thought it was all going to be OK, only to get into another queue as you head towards Edgware Road. Yes, Praed comes before a fall...

Where does the new one lead you? Over the Paddington Basin flyover?