I've played Costa Ballena a few times as well and would mostly concur with Emil's view. I really doubt that Olazabal has had too much influence on the design, but would assume he just licensed his brand. Biut who am I to know?
The best thing you can say about it is that it probably has the best practice facility I've ever seen. Probably not what an architect wants too hear, however one aspect too often neglected. Much of the revenue obviously comes from team trainings there (as Emil's example shows
- while I was there probably about half of the Finnish national teams were practicing there - impressive!) and I would believe it was planned with that in mind.
When it comes to the course, I thought a few holes were very well designed, the foremost examples:
The 10 is a reachable Par 5 double dogleg around a lake that plays into the prevailing wind (which was significant when I played there), so it offers some strategy for those who want to go there in two and weaker players still have to make a strategic decision: In the wind conditions I exeprienced they will have left more than 100 meters for the third and while the water will be almost out of play, the two bunker around the green invite you to lay up to the left of the green and have an easy approach.
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The 12 is also nice, it plays uphill and into the wind and thus also longer than it appears and offers a similar challenge for those who dare to go there in two and it offers a magnificent view of the ocean from the green complex.
However most of the other holes are not too interesting, overall I thought the Par5s to be the best. All in all it's good and solid work, but certainly not great.
www.top100golfcourses.com has it (1-18) as 65th in Spain. Holes 10-18 are nicely routed close to the ocean. While the course is spared from residential developments along it, holes 2-8 and especially 20-26 on the other hand don't have very nice surroundings and on some you have views of adjacent commercial structures.
So if Olazabal's input was Hole numer 10 he may be a good designer, however I would say this is just branding and Seville may have a completely different style. I don't know how qualified Mark's commentator is to talk about GCA anyway, but maybe I'm just the victim of German golf commentators being completely clueless about it.