I am in US, and I recently bought a Benq W1050, which is good. However, I just saw w1090 has a better contrast and lumens than w1050. I also found I could buy w1090(ht1070) at a lower price than w1050(ht1070a) in Benq's website. So is it necessary to return my w1050 and buy a w1090? I mean will there be a big image quality difference between them?