I like Manage only mode but don't play it much other than to jump in and act as manager for the odd game.
Two things I've asked to have added to this mode for a few years now.
1. The ability to hire my own coaches. AI Managers have this option, why can't the human manager?
2. The ability to have input on the make up of the active roster. IRL the Manager has influence there, we need this in OOTP. Really irks me when my GM gives me only 1 or 0 lefties in my 8 man BP.
If those features were added, ya, I'd play manage only mode all the time.