I think the gap is too far now. Linux people have developed all kinds of overlay file systems with very good performance. MX Linux live usb is as fast as when it's installed and all applications work awesomely. The installation of MX Linux is also a blink of eyes. The live usb version of OpenIndiana booted very slow and also very slow when running live. I tried to open Firefox and Thunderbird. Both applications take ages to launch and all of them crashed almost immediately leaving a big core file in jack's home directory. The installation process of OpenIndiana is also awfully slow. The screensaver triggered two or more times before it's finished.

OpenIndiana live usb technology is even losing to FreeBSD. NomadBSD offers a very stable live environment that is comparable to Linux. GhostBSD's installation process is extremely quick. I think it's time for you to have a look at it and make improvements.