Update: Based on there being enough potentially questionable (often, at best questionable) feedback regarding the unpredicatability of Level Airlines, both on this forum and also on Trip Advisor, I decided to pull the plug on the idea of returning on Level from Barcelona to Boston. Since my original booking for Boston to London was with Delta, I decided to modify that reservation by adding another flight to it, much as if i had initially chosen the Multi-City option. In retrospect, that would have been the best idea. However, I ended up getting what I feel is a decent deal and my wife and I will now be flying both to Europe and back on Delta. One short leg coming back is with their partner, KLM from Barcelona to Amsterdam. But all legs will now be Delta Premium Economy or KLM's version of it. I lessened the financial blow by taking out a Delta Airlines Gold Visa card. After I purchase $4000 on that card in the first 6 months (not a problem since I still have not yet paid for my March Norwegian cruise), i will get an additional 40,000 miles with Delta's frequent flyer program (of which I have been a long time member). The first year's membership for the Gold Card ($150) is waived and I also will get a $500 credit on my card when I have made those first $4000 in purchases. I will also get additional miles credit for having booked this entire trip through Delta. We have Premium Economy front row seats reserved on all legs of these flights. I will post back here after our trip to give my impressions of what Delta Premium Economy was like.