I am in the same situation. I have been working as a System admin for last 5 years. Working with Windows, Servers, AD, Vmware, Citrix. A year back I found another job where I work with a little part of cisco (Changing vlans, and ports and failover to other careers stuff) and I really liked it. That made me learn more about cisco so now I am studying for ccent.
yes, i understand the salary will not be juicy anymore because of the experience but for the long run, it will be better in case we get to ccie level.
I always wanted to go towards cisco but that didn't happen, may be this is the time. Lets see if this will help me. I already have a job and I am studying for cisco, dont know where it will take me but I stopped thinking about negativity and moving towards cisco more and more. I want to be expert in one thing.
What I think about Cisco -
Cisco is a ladder where I will go up and up.
What I think about Microsoft -
A tree and I can't jump from one branch to another like a monkey eventhough I act like one as a system admin.