Greetings,
We recently returned from a two-week trip to Spain, including the RS Barcelona/Madrid tour. When I booked flights months ago, I was able to get a good price on Delta's Premium Select cabin, flying out of a small airport close to us in central Illinois rather than driving to Chicago, paying for parking, etc., albeit at the cost of long layovers in Atlanta.
Our first flight to Barcelona was on an Airbus A330-300. To say I was disappointed in the experience would be an understatement. The seats themselves were indeed similar to Delta's domestic first class cabin, but similarities ended there. Overhead bins were extremely small and many people struggled to get their carry-ons stowed. I also had my RS Euro Flight Bag, which I use to carry my CPAP and items I want to access on the plane, which I had to put at my feet. Even when it's pretty full, I can generally squish this bag down to fit all the way under the seat in front of me. Not this time. I couldn't get more than half the bag under the seat, Not sure if there was an entertainment system box or if it was just the clearance under the seat, but this cut down on legroom that was already much less than I had been expecting. I can't report on whether the incorporated foot-rests were worth using, because the limited space made it impossible to try them. To top it all off, the power outlets in front of us didn't work. Were the relatively comfortable seats better than the back of the plane for a nine-hour flight? You bet, but overall it was far from a "premium" experience.
Our flight back from Madrid was on a Boeing 767-400. Night and day difference. Same seats but with generous legroom, ample overhead bins and functioning power outlets on a plane that felt newly refurbished. The woman in front of my wife reclined her seat all the way back without impinging greatly on my wife's space. All in all, worth the premium price for 9 1/2 hours of comfort with attentive service. And Delta flight attendants always seem generous with the wine pours!
Moral of story, I guess, is simply that the "same" cabin on different planes can vary greatly. This class of service has been retro-fitted into Delta's fleet and the results aren't necessarily similar from cabin to cabin. If I choose this option again, I'll definitely try to avoid the A330.