If you are already using SilverStripe or one of the developers behind it... good for you. But if you are planning to give SilverStripe a try, please don't. It will waste at least 3 days of your time and at the end, you will regret it. Just like I did. Here are the reasons:
The installation itself will fail because it will exceed php.ini default upload memory limit of 128M. Even if you temporarily increase it, you have to repeatedly mess with it, deleting _config.php, hit retry etc. I am sure the developers are getting kick out of this, but I find it extremely annoying.
Some of the basic features such as search, user registration are disabled by default.
You need extensive knowledge of the framework itself...but if that is the case, again, good for you. You make good money by billing your clients a lot of hours.
A lot of plugins require that you write php code to make them work. Why don't they just release one universal plugin which will ask the user to write appropriate PHP classes, then dev/build and everything is taken care of :)
Some plugins remove the only theme (simple, whose creator is sane!), making the site unusable. Others require you make an account on github, create tokens and all that crap. Yet others (Forums, multisites etc) only work on bleeding edge versions.. ofcourse, these dev versions have their own problems... like suddenly failing to work if you even touch _config.php or never really completing initial installation (although no errors). A lot of duplicate plugins. It only takes one plugin to screw up the whole thing and waste your hardwork and there is no rolling back! I have to assume if the intentions of the people who developed these are a little bit malicious. Or may be, these guys want to bill their customers as many hours as possible.
After you deal with SilverStripe plugin mess, you will go back to Wordpress and appreciate the wordpress plugin system :)
Security seems to be a joke! Several plugins (even SilverStripe itself) expect and even demand world-write access... that's right... they expect 777 on all files. assets, uploads, mysite, themes, mobile.
I read useless documentation, video tutorials (again I don't understand why they are created) and tried my best... I almost got it working.. but I have to admit, I made a terrible mistake by giving SilverStripe a try.