Thanks for the additional input Mike! I agree. I ultimately did not like the 'attached' sidebars and decided to space them out. I think it looks much better, so thank you for that suggestion.
I looked at your site, and I think it's pretty awesome. The first thing I clicked on was your "What we do" tab and I immediately got a sense of what your site is all about so that's good - much better than what I have going on :/
What threw me off a bit was your home page. At first I wasn't sure whether that was the blog or just a static home page. Maybe something you can do is style the home page a bit more (and with MD2, I'm sure that won't be much of a problem

) - similar to what Alex has on Kolakube. Or you can think about adding a feature box that highlights more of what your purpose for the site is, it's up to you. I personally like having the blog on the home page with a feature box (hence what I have on my site - haha), but that's just me.
Another thing I can suggest is to try to evenly distibute your menu items amongst the header menu and some on the menu below the header. I don't know if that matters much, but that's just what I'd do. Maybe you can put the basic stuff like your "About" tab in the top-right header menu along with your contact tab. It's not a big deal, I don't think, but maybe something worth looking into for easier user-navigation (perhaps?).
Your overall site is very clean and straight forward. I like it!