I cannot comment on the Transgo ones. I have never installed, let alone looked at one of those.

But the cheap ones from ZZP or WBS, as well as the good ole DIY shift kit are fairly easy to install. It only takes about a half hour longer to do when changing your trans fluid & filter. All total to drop the pan an install these spacers & maybe the springs would be 2 hours or so. I didn't find it very difficult at all.