I have the fictional Southern one and I really like it. Sometimes the pickups can be finicky but I've read that if you add some metal crew figures to the cab it helps with this. I've yet to find any that can fit in its very cramped cab though. I think there's a company that does WWI soldiers made specifically for this model however.
That said, the details are great and it looks awesome with any of the rtr stock that's out there. If you're doing DCC it has a speaker built into it out of the box. I got mine to go alongside the eventual release of the Lynton and Barnstaple Lyn because I heard the rtr Manning Wardles were pretty trash and I wanted another L&B style loco to match her.