How should I experience kernels

Today I had lunch with Philippe. He told me that L4 has a good, clean design, and many OS'es that are advertised as micro-kernels are actually not so. I'm into micro-kernels and I will have a look at L4 soon. So far I couldn't find the best way to experience a kernel. The thing is I can't, and actually don't want to try booting NetBSD, OpenBSD etc. on my host PC for that. It was my earlier intention. I haven't been able to do it so far due to time/hassle issues, but now I think that its also pointless. What am I going to run on my AMD64 with the usual PC motherboard, PCI bridge etc. it's irrelevant. I have Linux for that already. It's not gonna give me any broad perspective about the kernel itself. Instead, I think I should get a decent cross-toolchain, compile and try to run them on ARM directly. But before that I need to get more experienced on porting/booting Linux with ICE aid first.