Would Multisite would be a Good Approach for this Project?

I have searched support forums as well as tried to identify case studies of sites similar to the one we want to build to determine whether or not multisite would be a good way for us to go. I am still not entirely convinced, however, what might be the best approach.

I would really appreciate any feedback on how we’re thinking of approaching this site. We want to build with the best solution from the very beginning so I would truly welcome any guidance you can give me (or any red flags you can point out).

A bit about the project. It is one company with several departments. Although a similar look and feel will be applied to all departments, they do have some autonomy for how their pages might look and what information each department would put up in their sections. Each department would like to have control of content and post/edit their own information. We need to develop a backend ui that is easy for them to navigate. We do not want one department to see another department’s content or to be able to edit it.

Each department has information that they would be updating regularly (ie news, events, etc.). The homepage for the company would feature posts from different departments.

Currently we’re trying to determine if we should:

1) just do one WP site and have custom posts (news, events). We would use a plugin like Role Scoper (or it’s premium plugin) to restrict access for different departments. So logging in, one department will only see their information. The problem is, I’m concerned that it might get too messy. Additionally, I’m concerned about us relying so heavily on this one plugin to help us manage the background.

2) Multisite seems like a very clean and well structured option. I did read that if it is one company with departments with fairly similar look and feel, multisite might not be a good way to go. However, i’ve also seen enough examples on the web that included large universities and colleges where it seems like multisite might still be a good option. We would still use custom posts since the general content types are the similar across departments (though there may be one or two variations but I’m assuming we would just apply a different theme in those cases). We would use a plugin such as WordPress MU Sitewide Tags Pages to bring in custom posts to the home page. Though again, we’re trying to be careful about using too many plugins for the site as we want the site to age and grow gracefully.