Should I update ubuntu 14.04 to 16.04?

Question

Xen

The server is spinning:
RTMP
NGINX
PHP
MYSQL
PHANTOMJS + CASPERJS
NODEJS
The console offers to update. But I don't understand if it's necessary at all or not if everything works. Yes, and the update will have to be done by the method of a new virtual machine and installation from scratch of everything (XEN). Although there are no problems, everything was installed with handles and paths were prescribed. That is, all transfer this matter for 15 minutes.
Questions:
1. What will the update give?
2. Should I update now or is it too early?
3. Will there be a performance increase or not?

Answer 1

Works - do not touch !!
I'll stay for KO
1. fixing old bugs and adding new bugs :) (stupid answer, I agree)
3. nominally it will be as lucky. there will be more jambs with new versions.
For example, systemd was introduced in 16.04, and for some reason not all demons have configs for it :-/
if the server is not "heavy", and, for the test, it can be raised on other equipment, then copy, update, check for performance services, at the same time you will feel everything.