We have started playing basic Impetus at the club. The basic version is free and for an ancients game its very fun and doesn't bog down in Geometry wars. While other rule sets focus on weapon matchups Impetus focus more on the fight power of each troop type.
For example my 100 year war English knights are pretty average when mounted compared to French as the French have a huge bonus when charging without causalities. However my Longbowmen are hugely superior to the French crossbowmen but not greatly so to render the French helpless in a missile duel with my forces. The games between the English and French become and frantic game of can I negate the Impetus bonus of the French Knights before they hit my lines. Very much how I expect it to go without becoming boring like when we tried to do the same with FOG.
The game flows well and I highly recommend it to anyone. We had a few games outside period and it worked well.
Here are a few of my 100YW English.