I have mine at 11 words and yesterday I ranked number 5 on Google for Greenville NC lawn service. I keep every part of my pages as simple as possible.
There's another guy here that paid a company about 10 grand to design his pages. I did a similar search looking for his home town landscaping (he specializes in landscaping). I dug down through the first 100 returns and didn't find his website. I looked at his index page and he must have had 150 meta keywords.