Yeah so I don't know if its just me or what, but I noticed recently that some of my SERP title tags differ to that of whats embedded into their pages meta <title> tag. Has anyone else noticed this on their SERP's?

Anyways I decided to play with it some because I like to have my meta title tags in the structure of:
Code:
<title>[MAIN KEYWORD] - [SHORT DESCRIPTION WITH MAIN KEYWORD]</title>
And then start off my page's like:
[MAIN KEYWORD]
[SHORT DESCRIPTION WITH MAIN KEYWORD]
Page content with 1-2% main keyword density and 3-5 long tail keywords here...
And it seemed to work well for getting and maintaining my SERP's. But then as I stated above, "I noticed recently that a lot of my SERP title tags differ to that of whats embedded into their pages meta <title> tag." hence altering my SERP's. So I decided to play around with the tag structure on a couple of sites just to see what happened and which test worked versus which didn't.

On the first site I altered the structure like so:
<h1>[MAIN KEYWORD]</h1>
<h2>[SHORT DESCRIPTION WITH MAIN KEYWORD]</h2>
Page content with 1-2% main keyword density and 3-5 long tail keywords here...
And the second:
[MAIN KEYWORD] - <br />
[SHORT DESCRIPTION WITH MAIN KEYWORD] <br /><br />
Page content with 1-2% main keyword density and 3-5 long tail keywords here...
Now keep in mind that both sites I altered were in the same niche, same keyword and had the same meta tag structure...
Code:
<title>[MAIN KEYWORD] - [SHORT DESCRIPTION WITH MAIN KEYWORD]</title>
After doing the above test I gave the sites time to settle in and re-index and to my surprise the second test out preformed the first test. Now its only been a little over a week so I can't say for sure but its doing better so far. Is it just me or has anyone else noticed this on their SERP's?