Merseyrail is known to be one of the best networks in the country and has been ever since the upgrade in the 80s. The trains were starting to look a little shabby but they got upgraded too recently. It’s also one of the most reliable although I think they’ve fallen a peg or two during the transition of the new fleet and some new stations opening.
The underground metro in the city centre, small as it is with 5 stations that link across 3 separate lines, is clean, airy and really easy to navigate.
I think it’s about to hit a snag though. They’ve earmarked a new station for Liverpool Baltic, south of centre, where the creative and business hubs are booming, and will be very well received, but now with the new stadium opening the north of centre is going to be a massive bottleneck. They need a station in Vauxhall but they’re relying on an existing station which is above ground and lacks any ability to expand. They’re just adding a queuing system to the station entrance. Good luck with that!