I'm not saying FSG are perfect by any means, but I strongly disagree with the idea that ownership doesn't affect success. Again, the baseball story isn't a perfect correlation, but they took over the Red Sox in 2001, won the Series in 2004, 2007, and 2013, and have been highly competitive every year (they hadn't won it since 1918 previously). They came in, hired a superb management staff, made smart investments...etc etc.
I'd rather have owners who do have that track record of coming in and delegating the footballing decisions to people who know the business, instead of owners like Abramovich and Tan who are going to meddle. I'd love to see FSG engage even more with the city itself, and they have some really sensitive issues around the stadium planning...but this will be a good spell for the club.