I am a HUGE believer in knowing your own stats, and monitoring in a consistent way. For example: I get a DEXA scan every 6 months. The Dexa is considered the current “gold standard” for body fat testing and the reports give an amazing amount of detail about your body fat, lean mass, and bone density. Early on in my journey that report allowed me to see that I was dieting too hard, and lost some lean mass. As a result I was able to correct my intake and by the next scan I had lost more fat, and gained back that lean mass and more. every test since then I have continued to drop body fat and gain lean mass.
Simple versus complex: simple tests are a tape measure or a scale. they offer a one dimensional view that may be misleading. for example: a tape measure can not identify fat mass replaced by lean mass and a scale is only absolute weight. I think the more data points you have, the better off you are (at least this approach works for me, but I am a big nerd). I have a spreadsheet that tracks tape measurements, weekly measurements from the scale, results from my bi-annual dexa scans, and I also take photographs.
I feel that having multiple data sources tracked allows me to be more informed about what my body is doing and how I might react to different training cycles, adjustments in eating plans, etc.
If you are in Little Rock, you can get the DEXA scan done at Baptist hospital. here is the link for the service. The cost is $50 for first test, and $25 for each additional