I never said I had an 8714ES, only that I had used one. I have been using VNAs since the early 80's when the company I worked for bought an 8505. They later added various 87 series instruments, including an 8753D. Our production used 8711s first, but when they started dying, they went to 8712s. Since the 8714 is pretty similar, I switched from the 8753 to the 8714ES so it would be easier to develop the test programs used by production. Over time, I came to like the 8714ES better than the 8753D. I'm not saying it is a better instrument, I just liked it better for my use. Time passed, I retired, and now I want to do some hobby work. I don't feel I need to justify my needs or desires for a VNA. My priorities may change over time, so I don't really want to invest the amount necessary to buy even a used HP instrument. I think the Nano will serve my needs, and if it doesn't I still have a relationship with the folks I used to work for. So, I can probably use one of their instruments if I need to. Theirs are all 75 ohm, and since retirement I have gone back into the 50 ohm world, but that can be worked around. I don't claim to be an expert in the use of a VNA, but I know enough to do the work I need to do. The young fellow who replaced me has done wonders with regard to software used with VNAs. In time, he will be what I never was.