Complete flexibility and possibility to customize to the extent needed. However integrating third-party applications and services into Plone on top of existing APIs is a common practice just like every other CMS.

When it comes to SEO Plone takes the cake due to the fact that it is designed in a very, very search engine friendly way right out of the box. There is no need for SEO experts tweaking the website to rank well, all you need to worry about is writing good content and give it meaningful titles to out-perform way bigger competitors for top-spot rankings. The main point how it achieves this is the creation of well structured URLs and the way this links persist even after you renamed content and therefor created a new URL for it. An example: As a real estate agent you want to list your available houses in area XYZ. You create a folder "House in XYZ" and set a view for it that *yourdomain.com/house-in-xyz* shows the list of all the properties in XYZ. One actual properties is a pages with a titles "Beautiful 10 room pool villa" which is then available at *yourdomain.com/house-in-xyz/beautiful-pool-villa*. You decide to rename "House" to "Property", the new URL is then *yourdomain.com/property-in-xyz/beautiful-pool-villa* while *yourdomain.com/house-in-xyz/beautiful-pool-villa* still works and now points to the same content. Through this behaviour your previously indexed pages won't produce broken links. Furthermore creates Plone automatically RSS feeds from your content which allows customers to subscribe to or which can utilised in automatic newsletter creation with tools as MailChimp. If your main concern is being indexed best then Plone is a sure bet.

- Nice, stable, with a good user interface and an easy straight forward setup process. - We use it for a news portal, not the most complicated thing out there but it does the job and works nicely.