?I apologize in advance for the dreaded introduction: "It depends" but it does.
Here's things to consider.
MapInfo Native Tab files require good disk access. One of the reasons I am surprised that a number of SSA customers access their files on a UNC path to a different box is that this can never be optimal in terms of disk access and disk cache.
I do understand the problem they want to solve (single source) but I do wonder if they have negated the benefit of Native by doing it this way. Obviously, the speed of your network between Spectrum (not Analyst) and the file server can vary tremendously. VMs often have a shared physical disk so performance can vary based on use of other VMs. But by far the biggest factor is disk access including cache.
This is also one of the reasons why Spectrum Spatial is pretty cheap on memory.
Other reasons why Native TAB is a good choice:
1) Labelling of polygons is faster as the file has a built in label point (centroid).
2) Styles embedded in the table.
3) Internal knowledge of the structure allows us to do some smart things. The built in spatial index is always there. FindNearest is one of those.
4) Fetching data by key is fast.
Where Native is not always best is with non-spatial queries, particularly joins or more complicated ones. All that is our code and essentially done in memory.
With a database we have the logic in place to try and pass the query down to the database. Only when we can't figure out how to do this in the database do we have to process it ourselves. So a well tuned database with a good network connection can be great, can scale and perform without much help from us. Plus it has that single source built in.
Note managing data is still a job.
But basic rendering and mapping is rarely faster in a database. Like I said, with smart tuning, it could be.
In the end, understand what you are trying to do with your spatial assets and understand what your IT limits are. Sometimes the GIS or LI people in an organization have very little pull to get the resources they need, even if not very expensive. I had to sit with a customer's IT for many hours using a few different tools to prove that their disk access was really bad including a tool that did not use our code at all. Once they reluctantly agreed, they moved all their data.
Another wanted to move to SQL Server, all seemed ok but their connection speed between Spectrum VMs and the database was terrible.