The AJA card will improve your playback but you have to work in an AJA project. They are also very picky about which slot and what other hardware you use with them, so plan your system setup according to the AJA website. In fact they only recommend a handful of motherboards. The BM is also a cheaper alternative but again, you need to work in a BM project.
Vince Becquiot
Kaptis Studios
San Francisco - Bay Area