I appreciate what you are saying, which is why I stated 'Your mileage may vary'.
I use my VNA for general testing and development of antennas, matching networks, RF circuits and the usual stuff you would tend to do in a ham shack.
However if your background is from an RF development environment. Where you are used to using VNA's etc on a daily basis, and simply wish to have a low cost version of a professional instrument at home. Then your usage pattern is likely to be different.
I find that for quick, easy measurements the Aim user interface and general product attributes. Make it very quick and easy to make sufficiently accurate measurements for my purposes.
I do use the SDR Kits VNWA3 - just not as frequently as the Aim's.
I guess it's a bit like why some folks like particular brands of cars - they will all get you from A-B but you feel more comfortable in some models - but it's not always easy to say why - It's just down to personal preference.
Martin - G8JNJwww.g8jnj.webs.com