body stiffening

My original thought was that while the US Car Tool connectors that follow the floor pan are undoubtedly better, this project is a significantly bigger proposition than the bolt in types. Between pulling the interior (to avoid a fire), prepping the surface, modifying the braces to fit, welding them in, this easily could become a very expensive job, assuming you're not a welder yourself.

So...I bought a set of the Mopar Performance bolt-in type which are still in their shipping box. I plan to have them welded in which according to my local shop, shouldn't require anywhere near the prep of the Car Tool type and should offer a lot of the benefit.

What are your experience with these? Should the benefit of connectors be obvious? How do you know they're not working?