I would choose Barcelona over Chelsea/United/City any day of the week and I wouldn't give a flying feck about their prestige or the EPL being "the strongest" league on the planet. That's how much of a difference living in Barcelona/Madrid makes, as opposed to living in the UK where the food is very meh, the weather is fecking meh and, let's be honest, the people, especially the new generation, are extremely meh.
In regards to underhand payments, I'm going on a limb here and I'm saying that most big clubs do it. If City do it and they aren't caught, the others are likely to do it as well.
A few years back I had a choice between Barcelona and Frankfurt for a job. I went to Spain without thinking a second about it. Then I had the same choice, stay in Spain for an extra year, or go to Frankfurt/Manchester. Again the choice was very very easy, even if the pay would have been bigger in the other two cities.
Moving on, I very much agree that Madrid/Barca can do this kind of shit in public to players and still retain their attractiveness for players. I think it's mostly Spain actually, especially for Latin players like Raphina, Bernardo, etc. It's sickening, but it is what it is.