Looking for feedback about "look-ahead" navigation

[TopFloor]

Our company has been creating websites where the navigation is developed in such a way as to allow the visitor to get a preview of the image and/or content on that is on the page.   Here are two websites that use this technology:
http://www.uniquepadprinting.com/
http://www.empathia.com/ (On this site, the previews are only available if you click on "Whole", "Productive" or "Safe" at the top of the page.

I'm looking for feedback such as:

• What do you call this type of navigation (We call it look-ahead, but I can't find much info that term on the web)
• Have you experienced any issues with this type of navigation?
• Do you have any recommendations on it?

Some of the things we've seen are:

• It adds the same content to every page of the website
• It creates a lot of internal links
• It can create a lot of code on pages
• It can slow page-load times

 

[Chris.Menke]

I think developers think too much about how their code impacts search results.  It's the visual content that is most important to google. As long as it can crawl it, you're generally in good shape with the code.

[TopFloor]

Hi Chris,
Thanks for your response.  I'm glad you like the look; I agree it can be a cool addition.

However, I was surprised that you stated the sites don't add much code.  If you take a closer look at the code of any of the interior pages of Unique Pad Printing, for example, you will see that the navigation takes up over 200 lines of code.  Original content doesn't appear until you get to line 411 of the code.

Compare this to another site, such as http://www.industrialvacuum.com.  The navigation only takes 30 lines of code, and original content appears in line 124.

[Chris.Menke]

I'm not sure it does any of those things.  It does create additional code but not much.  I think it's kind of cool.  Would be nice if the display block were clickable, though.