Personally I think they are worth it. It always depends on your situation and what you want to do in the future. If you work as a manager/admin in a strictly windows environment and you know the future will be windows and you don't plan on changing jobs then ya vendor specific would be perfect. I personally like the broader range that vendor-neutral certs give you and of course most of the concepts you learn apply to any vendor product so it gives you that solid baseline understanding.
I believe you would be surprised at how much attention employers give certified professionals. It's the same concept as someone with a degree and someone who is just really damn smart. Unfortunately in this world it really doesn't matter how smart you are unless you have the "paper" to back you up. I know so many people who just fluff off certs and they are really intelligent people that could easily do a way better job then most administrators, but because of this lack of drive, then end up working at a help desk for countless years. Certs aren't just a fancy piece of paper to flash around, it shows character. It shows that you want to continuoulsy learn new technologies and then to prove to yourself that you know what you're talking about. I give lots of respect to those with many certs as you know they are always studying/learning and pushing to learn more and more and pushing themselves to be their best.
Well there is some babbling from me....I don't know your entire situation but taking Network+ would be a good next step, or if you want to stay more towards vendor specific then more then likely take you Microsoft Certified Professional exam. Either way in the end certs give you pride, confidence and in most cases some extra money for your efforts. Good luck to you.
A+,N+,CST,CNCT,MCP