I've been flying Air Nostrum as well as Iberia Express an awful lot lately, but always in Business class where they serve a nice hot meal and drinks. I thought they gave out water in eco, but I'm not sure if there is a cost.

I've done online check in with IB on the IB flights and BA with the BA flights. And I think you can even download a BP to your phone from an already checked in leg. That's worked for me at least. YMMV.

And regarding an above post about them being in the K gates, in my experience it can be K or J or L. You have to look at the monitor. Or if you online check in and use the IB app, you should get an email and SMS with the gate info. At least that works for me. And the service has been great with all flights reasonably on-time. I'm a fan.