I have not played a byz in early myself... but I am doing a turk early one... and I personally think the byz should rush into killing he turk asap... because the turks like the byz have only a few province that can build units off the bat, and they get a really crappy army at the start too.. (Except for being able to build armenians very soon) but once they are able to build armenians, saracean/muhawid spear, and turcomen light cavs they are quiet a force to be recon with... but if you take out Rum and probably armenia right off the bat the turks are effectively gone from the game... with no unit producing province and no money making province for that matter

Byz army have some real issue in dealing with good calvary archers.... unless you can get stepp cavs quickly ... but the turks don't get much quality cav arch until a few yaers in....