Workflow or Process Builder?

I have a workflow I just set up that is working just fine.  Criteria is:

Opportunity: Opportunity NameequalsRenewal Opportunity with a field update and this formula:

Account.Name & " " & "Renewal" & " " &

CASE(MONTH((CloseDate)),

1, "January",

2, "February",

3, "March",

4, "April",

5, "May",

6, "June",

7, "July",

8, "August",

9, "September",

10, "October",

11, "November",

12, "December", "None") &

" " & TEXT(YEAR((CloseDate))

))

Like I said it is working fine, however we are moving to lightning in 2018 and everything we build in our org moving forward we want to build with that in mind.

Is there any advantage in making this a Process Builder if we will be moving to Lightning in the future?  Workflows don't go away in Lightning right?  And they also trigger before a PB would.

Just looking for opinions on either method.

Thank you.