It's not much of a wager.
Off hand I can only think of three clubs whose fortunes and finances have improved simultaneously with new owners. Chelsea, Sunderland and City. Everyone else has been a disaster. Maybe LFC's new owners will come good but its still early doors and they went through the jaws of administration to do it. Sunderland success is only moderate. They spend 30 m a season and have gone from a yoyo club to a premier league stalwart - what a waste.
Villa have gone nowhere. Despite spending and selling sprees.
United still win and buy but they were doing that with the previous owners. The time bomb is ticking on 700 million in debt though that could yet see the club collapse.
Blackburn bought by the Venkys in a fanfare of "we're heading to the champions league, we're gonna buy ronaldinho and beckham." Since which they've sacked a decent manager for a poor one, sold most of the best players at the club and reinvest about 5% of it.
Newcastle continue to be run like a comedy circus. Relegation, a good season last year, but I have every faith they will be in the bottom 8 this year due to mismanagement as much as anything.
I'd spend an hour on this post if I wanted to list the complete fück ups - portsmouth, southampton, etc.