SPQR is a total modification for R:TW. The changes encompass all areas of gameplay with added focus on the Roman military machine and the system of recruitment and training of both pre-Marian units and Legions. Special care has been given to the battlefield experience which features the longest battle times of probably any existing mod making tactics an essential component of the game. Definitely not for people accustomed to blitzkrieg tactics both on the battle map and the campaign map.
This is the Readme for SPQR Total War 8.0, it is in PDF format and will explain the changes and features in the mod.