Site icon Hip-Hop Website Design and Development

Which is a better WP setup: WordPress Multi-sites or Multiple Single WP sites?

So I am pondering over a decision to use WordPress Multi-Sites or just use Multiple WP Single sites. The reason is that the company site is broken down into multiple departments.

Maindotcom (WP SITE)
 /about
 /department1 (WP SUBSITE)
 /department2 (WP SUBSITE)
 department3.maindotcom (WP SUBSITE)
 /contact
 /blog

I would like…

I have looked into using WP HyperDB which has the ability to add on remote servers and Master/slave setups.

And I have seen solutions to share same user across multiple installs using HyperDB: How to use hyperdb to separate and share a user dataset between wordpress installs?

Please let me know any solution