Hi everyone. Unlike most people here, I only have a Dolby Prologic System. Last year I was considering upgrading to a 5.1 system since I was tired of having some great DVD's but not realizing their full audio potential. But then THX-EX and DTS-ES recently came along...well that just screwed everything up. So now Im still stuck with a Prologic system, and my family isnt too cool with the idea of shelling out alot of money for a new receiver. They wanna know if 6.1 is really going to sound THAT much better than our current 4 channel system. So for anyone out there with experience, can you please tell me if a new 6.1 system is going to make that big of a difference in my home theatre. Will the sound feel larger and more atmospheric? In fact, Im positive it will, but I just wanna be sure so my family cant get in a big "I told you so" on me. Also, I know that if I do get a new receiver with THX-EX and DTS-ES, Im gonna need some new Surround Back speakers. Can I get by with just one, or should I really go for 2. And can you recomend some good surrounds too? Any help would really be appreciated. Thank you.