The Derwent Valley light railway near York.
Yeah... long time since I've been but it's not long enough to spend any length of time there. Nor does it go anywhere.
I wouldn't suggest the Middleton railway to anyone who wishes to see the best of Leeds!
I haven't been for years, but I don't think people have high expectations of it, it's an unpretentious line that doesn't claim to be beautiful and has its niche focusing on industrial loco's and locals who just want a steam train ride and for whom any steam train will do. For that reason, to me it's not a disappointment as it sets limited expectations that it does at least match.
The Middleton Railway has a lot on display that visitors can see, plus it's very clear what it is - a preserved section of an ex-colliery railway, using the original formation from pre-BR days, and has a museum at Moor Road plus at the far end is Middleton Park where you can literally walk up to (and stand in) some of the old colliery seams and bell pits. I think it's alright for a few hours for what it is.
As for my contribution to this thread...
It genuinely pains me to say this but I think at present, the Embsay & Bolton Abbey Steam Railway doesn't have a whole lot to offer for more than an hour or so. It's a 15 minute ride each way, which is picturesque but some of it doesn't have much of a view, very little at either end of the line other than a cafe and shop and Bolton Abbey villlage is a 33 minute walk from the station.
As I've said many times before, I love it as a railway, love their traction fleet, they're doing a brilliant job refurbishing their rolling stock and I have got some brilliant memories of visiting as a child, but it needs an Oxenhope-style exhibition shed, or a museum or something else at one end or the other... or they work with local attractions like the Priory and Billy Bobs Parlour to make themselves part of a multi-site day out... at least until they can extend a bit! And I sincerely hope they do manage to do something like that!