Clean & fast. I'd be inclined to combine the "about Kestrel" info with the photos on the home page,with just one logo, company title & subtitle at the top.
I'd agree with getting rid of frames. It's also nicer to give the pages titles rather than have "untitled document" show up at the top of the browser. Also a typo - the home page is copyright 2004 but the rest are 200.
My preference is for thumbnails to open the bigger picture within the website, keeping the nav links rather than open a new page with just the picture.