You heard the reasons why you should move to SharePoint Online and the some of the things you need to be aware of, but let’s step back and consider the reasons why you might not want to make the move to the cloud.
1. Lack of Full Blown Central Administration
There are SharePoint admin functions with Office 365/SharePoint Online, but they are pretty limited. This is because Office 365 is multi-tenanted SaaS (software as a service). This means that many organizations are using the exact same implementation of SharePoint as you are -- wouldn't pay to give you central administration functions that would affect other organizations would it?
Some of the important admin functions you won’t get:
- The ability to control to the list view threshold (you are limited to 5000 items)
- No web applications
- No analytics
- A number of fine tuning options such as quota templates, resource and request throttling, managed accounts and more.
What this means is this: if you have an existing SharePoint environment that you have adjusted greatly through central administration options, you aren't going to want to move to a cloud-based version if you absolutely need those customizations. Make sure you know what administration functions you can have, and if you can live with that. If you can, if might make sense to make the jump.
Again, customization doesn't really work when you are living in a SaaS-based SharePoint environment. Yes, some customizations are allowed, such as some branding, but there are a lot of typical customizations that aren't allowed.
Consider the web part. One of the first things many organizations do when customizing SharePoint is build their own web parts. It doesn't happen the same way with SharePoint Online. There are ways to incorporate third party content into your implementation using the IFrames and what Microsoft calls app parts.
App parts don’t actually reside with your SharePoint implementation, you host them in a different web application, using an IFrame to surface UI elements within a SharePoint site. This is one of the new approaches to custom development in SharePoint (both online and offline). In the SharePoint online case, it means managing and paying for another environment alongside SharePoint, essentially adding to the cost of your overall SharePoint environment and eliminating any benefits to not having to manage your environment.
3. Limited Feature Set
Everything that comes with the on premises version of SharePoint is not available via Office 365 / SharePoint Online. I talked about some of these from an admin perspective, but there are also some nice features you can’t get either. Here are a few examples: