The gain 4 Silvers option is quite underrated. First of all, using your Trusty Steed as nothing more than a single, more flexible Level 2 City just isn't that awesome.
Beyond that, a deck with Trusty Steed may very well be a deck that greened early, in order to match Province to Tournament. In many cases where you have Trusty Steed, you already have Followers, or are suffering Attacks from your opponent's Followers. In both these cases, gaining Silvers is a nice boost to the average $$$ of your hand, because Followers' Estates and Curses really do sap the vitality of your deck. Also, your Tournaments will start getting blocked, and are no longer reliably worth $1, so you do need money.
If you never find yourself hitting "gain 4 Silvers," you're probably underusing the function quite a bit.