Gotta say that I think multiple opsystems is the best way to go. Can't see ignoring whole categories of computing when there is so much interesting stuff in each of them. I have run across professional linux/java people who admit that .net rocks and just wish that it wasn't so tied to Microsoft.
I am personally into java, .net, linux, and various database systems, etc. I am just now getting back into Amiga systems after a long hiatus and mostly because of the FPGA aspect of it.
Paul L