<font color='#000000'>I didn't have the chance to side-by-side test the 5ES and 4ES but when I learned that I can buy one of the last 5ESs at heavily discount price I was very confused. For the 4ES i can buy anytime, it has 12V trigger, more amp. But when I compared the MSRP between those two, it doesn't make sense. YOu get more features for less price for the 4ES so I believe sony must cut cost somewhre. Maybe inside the receiver, labor or QA test. Now I am still very happy with the 5ES but I don't know if I should've bought the 4ES instead. I believe the 5ES has high quality than the 4ES that makes me think the 5ES sound better but it is not always true isn't it?
I think Sony made the right move when it justify the new 4ES receiver to compete in the market. it's very much general practice in many companies. When they first design something, they use the best parts to make sure it work correctly and less debugging variables but when it works, they go to the other source to cut cost.
Well i don't know what I am talking about.</font>