The FA Cup, final match will be played today in the match where both the teams are in great form. It will be a tough fight to win today's match, the team that can attack well in the final will be the champion. Manchester United is a strong team but not performing very well at the moment. But Manchester City attack well enough to win every one of their matches and in most of the matches they win brilliantly.
Not sure which casino you use, but the odds is really bad, in sportsbet.io the odds for Manchester City to win is @1.61, this would make huge bettors earn more profit by placing their bet in sportsbet.io.

It's funny how you can say Manchester United are in their great form, there are three good players in Manchester United e.g. Antony, Martial and Martinez. Manchester United mostly scored 1-2 goals, it's not a fantastic winning. Manchester City is better in attacking form because they mostly scored 3-4 goals.
This mean, in any perspective Manchester City is better than Manchester United, the only one hope from Manchester United is luck and the referee favor in their side lol.