Pros
I love the ease of use, rich functionality and simple customization process. Microsoft is a huge player in the market and therefore investd a lot into research and development, and have recently committed to a 6-month update rhythm, meaning you get more features, more quickly than ever. Plus, it sits inside MS Outlook, and allows you to track all your emails, appointments, calls, and more to individual clients with the click of a button.
Cons
The latest release that we have, CRM 2013, is a bit bland looking with lots of white space. It could be designed with a little more flair to be appealing and easy to read. They changed a lot in this version and not all of the changes are good. They eliminating one function on the sales side that I used all the time and I am not sure I like it. When converting a lead, you used to have the option of checking off boxes to create the Customer, Contact and Opportunity and you could also check "Open these records up conversion" so you all of them popped up in separate windows so you could finish adding details to each of them. Now, there is no window for that, and it just creates the Customer Record and Contact record in the background for you, but you have to go out and open it yourself. A lot of our salespeople forget to do this and just edit the Opportunity Form that opens with you convert the Lead. Microsoft does this sometimes, thinks that they are improving something but fail to actually ask those who use it. I wish they'd do more to include current customers in the design process.