i own a 46g10 , which has identical picture quality to the g15 , and i had a 46b650 for a week , which is identical to the b750 apart from not having 200hz ...
i felt the samsung was slightly better with sd ..
i thought the g10 was better with hd ..
both are good with motion , but the samsung could look quite weird unless set up right , the b750 will probably be the same ..
i did play some mkv files on the samsung , and they worked fine , it is a nice feature ..
id buy the g15 , but i wouldnt be too dissapointed with the b650 , b750 either..