I took the Alfa Pendular from Lisbon Oriente to Tunes (in the Algarve) a few weeks ago, the 1824 departure from Lisbon.
I paid €17 one way in First Class, booked in advance on cp.pt. I received a SMS message as my ticket (UK mobile phone number) which I showed to the ticket inspector on the train. All very seamless.
There is a lounge at Oriente in Lisbon. It has chairs, a coffee machine, some newspapers and a couple of TVs showing rolling news. And a departure board. There was wifi I think but I didn't use it.
Onboard, after we left Entrecampos (the last Lisbon stop before heading south over the bridge), the staff came around with newspapers and then a trolley serving tea, coffee, water and juice. About 20 minutes after that they came through with the pre ordered hot meals (and I think you could have asked and paid for one on the train without ordering in advance). I didn't see what the food looked like but it smelled very good!
I sat in a table of 1 facing, but there was nobody opposite me. I had my own 2-pin plug to run my laptop and charge my phone.
The buffet car was a short walk away, and a 250ml bottle of red wine was a couple of € (3? - can't remember but it was cheap!)
We reached speeds of 221km/h on the line south of Pinhal Novo, but most of the journey was slower than that.
We left late, but arrived on time. The train was about half full in first, second looked quite busy.
All in all it was a perfect journey and a very good value way to travel.