I like Hayasdan, the reforms just add that extra cool factor, plus, you can vary your playstyle depending on the enemy and your preference. You have access to good factional horsearchers, plus skythian regionals. You can go fully eastern style with good heavy cavalry and your FMs are monsters on the battlefield (+ factional kataphraktoi) and good foot archers with the expendable/ token infantry. You can even play "classical infantry" style armies if you are creative. You have some decent high-end infantry, plus access to decent Greek infantry in Asia Minor (as local troops) ie. Classical Hoplitai, Thureophoroi, and even Pantodapoi Phalangitai in 1 or 2 provinces.