Can anyone tell me which of the XL cars Sky deck single side seats have unobstructed windows next to them and not some window frame blocking part of the view? I have looked at all the pictures I can find and it's hard to intuit.
I take it that you are aware that 4 different high speed train companies (Iryo, Ouigo, Renfe & Ave) are on the same tracks between Barcelona & Madrid? https://www.thetrainline.com will clearly show you the times and prices for all the services (best to select Euros as currency) - otherwise, it looks like you will have to go to each individual website.
I can't comment on the merits or otherwise of these different high speed trains but if you Google You Tube and then each one in turn, you will find various videos uploaded of each of these services showing the different classes on board.
Here is one for the Iryo train as an example.
Ouigo is the low-cost carrier, no frills, no food car, all second class. Unless you buy the upgraded ticket, you can't choose your seat. Personally, it's not my first choice.