The advantage of a month to month tenancy is that you need not give a reason to terminate the lease. Depending on your state, all you need give is a 30 (or 60) day notice to the tenant.
However, a month to month lease does not negative the need to go to court should the tenants refuse to vacate. In other words, you still cannot do a self-eviction (i.e., take it upon yourself to remove them physically). You still need a court order to do this.
The month to month tenancy can get the ball rolling faster on the entire eviction process. For example, a landlord might give a 30 day notice, followed by a 3 (or 5) day notice to vacate the premises. If this notice is not followed, they can typically go to the court and file for an eviction, thus beginning the process earlier than having to wait until the end of the 30 day period.
I hope this makes sense.
Gail