Great Western Railway is having a sale through January 19 for trips through March 29. Same day return tickets are now just £30. I've never been to Wales let alone Cardiff and I am intrigued about doing this. Specifically I'm thinking about doing this day trip on Thursday March 21.

I don't mind the 2+ hours on the train each way because I am traveling with a back condition so being seated on the train and walking around occasionally doesn't sound so bad.

Are the trains between Paddington and Cardiff some of the newer GWR equipment and thus are the train carriages in 2nd class comfortable? GWR says it offers "buffet service" so at the very least I'm assuming it has a dining car? I can always bring something on the train.

In Cardiff, I am interesting in walking around, visiting bookstores, seeing churches, perhaps going to the waterfront and taking a boat ride assuming they are available in March. I may visit the Cardiff Castle. I want to enjoy a nice lunch.

So is it worth it to do a day trip like this especially in the middle of March?

Thanks for any input.