While I do appreciate preact, and have used it... it doesn't contain all the error detection and messaging that react proper does... that's where a lot of that much smaller initial load comes from. When you aren't having issues it's great... if you are, less so.

It really depends on your needs, you can get a very small app/module via preact, and I like it a lot. If you're building for a larger environment, or larger applications, you may be better off eating the extra 60-80k or so for React proper.

Hi, what we do is use a React build in development mode and then compile with preact.

This is safe at least for us because it allows us to keep all the good React development environement while providing a build that is a lot lighter.