The XDA IIi is a new model designed to supplement the current XDA IIs. Its essentially the same except that it has a better (allegedly) camera and a 624Mhz processor instead of the 400Mhz version found in either the XDA II or the XDA IIs.
Its only a worthy choice if you need the extra processing power or better camera, otherwise the XDA IIs is a very good buy at the moment. I wouldnt go with the XDA II anymore, its old hat now.
Current: iPhone 4
Past: iPhone 3G, iPhone, HTC TyTn II, HTC Touch, Nokia N95, Motorola Z8, Qtek 8500, T-Mobile MDA Vario, SonyEricsson W900i, SPV C550, SonyEricsson K750i, Nokia 9300, I-Mate Jam, C500, Moto V600, SonyEricsson P900, P800, Treo 600, SPV e200, Nokia 1100, Nokia 6230, SonyEricsson K700i, T610, Nokia 7650, SonyEricsson T68, T29, Moto T250, Nokia 8310, Samsung A100, SPV Classic, Moto V50, Nokia 7110, Vodafone EuroTel
Stress is when you wake up screaming and then realise you havent fallen asleep yet!