I've only tried it in virtual machines. It feels slower and more sluggish than OpenIndiana (which is based on Illumos, which is the post-Oracle open solaris) -but I don't use OI a whole lot either.
Since there's an opening I'm curious about something mentioned earlier in the thread, so I'll ask.
It was said earlier that SunOS included a compiler, but it was dropped in Solaris. Was it possible for people to carry over the old SunOS compiler and use it on Solaris? Did people do that, or did they just have their companies spring for the actual Solaris compiler?