My price quotes were for BritishAirways outbound, Iberia on the way home. I just looked at the seating in Premium Economy on the Iberia A330, which according to the website is the plane on that route. Seating in PE is 2-3-2 instead of the standard 2-4-2 in regular economy. So I the seats are wider, and there is a smaller,dedicated cabin to this class. And generally the food is better to PE than regular economy, but that is airline-specific so you need to check on that.
Up to you, but you should think about what you want out of business class, and whether it is worth $1000 more to pay for the difference between PE and business class for a daytime flight on your way home.
We have been flying business class on British Airways for the past ten years, courtesy of our accumulation of miles. It is very nice, but I would not be happy paying for these trips at full price, which is usually around $6,000 and up. From time to time, we look back at Premium Economy when we board, and for the flight home, my husband asks why we are paying so much to fly business class for a daytime flight, when PE looks almost as good? (The answer for us is that we are using miles, not paying full fare, so there is little difference in $$$).
And what is the benefit of lounge access at 10 am or other morning time, which is the usual departure time for the Westbound (to the USA) flights.? Free coffee and tea, and snacks. Is that worth $1000 extra to you?