I went with a friend to Peninsula Valdes in Sept 2017.  We flew in to Trelew and rented a car.  We did need to taxi from the international airport to the domestic airport in Buenos Aires, which was a bit of a hassle and took up a bit of time. 

 The driving itself was easy and uneventful.  The roads were fine and we arrived around dusk.   We spent the first night in Puerto Madryn, which is a small city south of our destination, which was Puerto Piramides, a tiny town to the north.  We drove to Puerto Piramides after breakfast the next day.   On our way up, we pulled over many times to enjoy watching the frolicking whales, which were astonishingly close to shore.  In some places, you could see 6 or more in a glance.   We were pleased with this, since wildlife viewing was the purpose of this excursion.  

Our excursions in Puerto Piramides included the Yellow Submarine whale viewing, and we were not disappointed.   There were many, many whales and dolphins.  It was a bit crowded below deck so we mostly were on top. 

We drove up to the point and hiked down to the beach the next day.  There are vast sheep ranches in this area, and guanacos, burrowing owls, some kind of wild cat, an armadillo (sadly, deceased) and many birds were seen on the drive.   At the beach, we saw vast numbers of sea lions and a few sea elephants.  We looked for, but did not see, several male penguins which had arrived ahead of the flock to start nesting.  We were too early in the season for penguins, apparently. 

We saw orcas through the binoculars and learned that the big, famous male who instigated the sea lion beach snatching hadn't been seen in two seasons and was presumed dead.  Of course, nobody knows for sure.  He was the subject of many spectacular photos and documentaries, but don't assume you'll show up on the shore and witness such an event.  Apparently that brazen hunting strategy was only partially adopted by other members of the pod, and was mainly done by that male.  

There are some very interesting rock formations (the Pyramid point).  I would have loved to do the snorkeling with the sea lions, but we did not have time in the schedule.  In Trelew there was an excellent dinosaur museum.  

If you are a fan of nature, marine life and like huge open spaces, this is a great spot to visit.   We spent 4 days and loved it all.   A city lover might be a bit bored out there, though.  The small hotel we stayed at was very minimal, with little to no soundproofing, but had a comfortable bed and hot water.   The food in town was good and well priced.   There are some large ranches scattered around the peninsula that cater (all-inclusive )to tourists, but we preferred the budget hotel and our own itinerary.