Played my first game of the new ancient rules, Hail Caesar today. We have been playing Black Powder for some time and the mechanisms are similar. So the learning curve was not too steep.
I brought an Ottoman army with a foot division based on Janissaries and two flank divisions of cavalry. My opponent brought a Wallachian army. Although the rules don't have a cut off date, there aren't many troop types for the medieval period, so you need to improvise.
The game was very enjoyable and like Black Powder full of uncertainty in the movement phase. My left flank stubbornly refused to move for the whole game. Other divisions charged across the table and got into contact quickly. What we really like is the simple mechanisms and the absence of micro measurement and other complexities that complicate other systems.
We really do have a glut of good rule systems at present. All have their strong features and I expect we will play most of them for now.