Have reported on this just by chance-as I did the ride to Tarragona last week and answered a Q here on T-Dia for Barcelona area.
Dep. <9.00 from old estacion de Franca, passes Barca rail tunnel, Sants at suburb. platf dep. 900-was >60 mins late, was a 4 car Regional Expresss elctr.set, heavily graffitied, no excuses/explanation at all about delay, with a very good load of people. I used the also delayed following 9.30 (same route, till Reus), same type of set. JUst after passing Sitges my train stopped, waited, was then going back to Sitges where this Mad set was standing, failed and we loaded its load and our train (no announc at all, nor any excuse/exlanation) then turned into what I later saw was the replacement tren to Mad.-delay then well over 90 mins! Its a 4 car set without any refreshments.
Yes, in the past I have also done this old line-and also some of the variations on it between Zaragoza and Barca- still as espreso or even overnight.
Fares'for this tren fixed 45€ (=roughly same as most bustickets), AVE is demand-responsive and from mostly about 80/88 till well over 125. The now also running low-cost AVLO or Oui-GO (double deck TGV) sometimes offer promotional tix for 9.99, mostly around the 30/40 mark though