Here is my take
If you have foil from the stock install messing with the signal, (tons of reasons)
The isolation mod will help, the concept is simple and sound. The kit is neat and tidy compared to the cardboard.
some have no issues stock, some do.
I installed mine for the first time prior to the last firmware update.
And got lock for the first time setting in my house.
So it appeared to have improved performance.
Then the firmware came along, and now most of the time I have lock by the time I have done pre-flight checks., less than 1 minute.
Having said that, there are still times and locations where lock takes a very long time on initial start up.
So much has to do with the environment at the time, that is why I think some people report no improvement.
For me given the price and the workmanship of the mod. It is a good investment
One other thing to remember about solo and lock compared to others.
One of the reasons you do not hear about Fly Aways with 3DR compared to others, is the pre-arm checking is more thorough.. I personally would rather sit on the ground and wait for the electronics to determine system health than fly away hoping a good lock was had.