I've been meaning to write a similar review but you're much better at it than me. I've been playing with BBO for 4yrs now. So it was natural for me buy at set of 4G when it came out.
Less power, less spin... I did use my ATS ERT to measure the tension loss over 3wks in my bag(it went back in my bag after 10mins), and it does hold tension well. Other than that I have nothing good to say about this poly.
If you think 4G plays good, get yourself a set of BBO and be amazed.