6 days EM and then Seville
 

Looking to spend 6 days in Extremadura next April and then 3 days is Seville. I have been recommended to spend 3 nights in Caceres and 3 nights in Merida. Now Im reading that Merida may not need 3 nights and can be cut. Should I have another base instead of Merida for all 3 nights or should I have 1 night at Merida and 2 somewhere else? We will have a car.

Where do you pick up the car?

Madrid airport Im thinking, after arrival and then drive to EM area

I would suggest spending the first night in Orpoesa. The next day take route CM 4100 from Oropesa through Guadalupe and Trujillo to Caceres.
Merida is an interesting town and makes a good base for day trips to the castle ruins and hikes in Medellin, Magacella and Alange if those interest you.

I'm always a bit skeptical of these "how many nights" questions. I rather liked Merida; on my 2014 visit I think I stayed four nights there, with no regrets. I could have stayed longer. Then again, there are others who might consider four nights too many, or insufficient. To me, three nights in Merida -- which means two complete non-travel days -- seem adequate, though perhaps minimal.

Never upon my leaving Spain, or any other country I have visited, have airport authorities examined by itinerary to see whether I had visited the authorized "must-see" destinations, and spent the "required" number of nights in each.

(By the way, I think Extremadura is a great choice.)