If you were to browse the list of websites I work on you might notice Perch mentioned a lot. Perch is as they call it, "the really little content management system" and I love it.
Being little is good because little is easy! It is easy for me to setup and easy for clients to use. Being simple is its greatest feature. After all, simplicity is the greatest innovation!
Simple on the inside and simple on the outside. When choosing a CMS I think the most important factor is how easy it is for clients to use. Perch has a very straight forward administration that can even be rebranded. I doubt it would take any longer than 15 minutes to show a client how to use it.
For web designers:
Perch isn't like WordPress. It doesn't come with any themes or templates. The front-end HTML and CSS of website is 99.9% under the developer's control and I think this is great! The entire design and functionality of the website is still in designer's hands.
Someone who doesn't know how to code wouldn't be quite sure where to start with Perch as it isn't intended for novices (at least when it comes to the website itself). However, if you're a web developer then it is actually very easy to build into any website, even an existing one. Almost as simple as a "<?php include('perch/runtime.php');?>" here and a "<?php perch_content('Content Area 1'); ?>" there.
Perch isn't just limited to small sites. I think it can scale quite nicely to larger websites too. There are already a number of "apps" that extend its functionality. In fact, I use Perch along with the Blog app on this website. I love it.