I am an alumna of the 2005-6 Hamilton College Academic Year in Spain (HCAYS) I was there both semesters and was very happy with the overall experience.
It was encouraged that students do the entire year, but not mandatory, however I feel I benefited from the language immersion over a longer period of time as well as the advanced grammar classes for 2 semesters. Being obligated to speak in Spanish, though challenging, has paid off, and I recommend the program specifically to students who want to take their Spanish to the next level. Additionally, as someone who was majoring in Hispanic Studies, I was able to fulfill many of my requirements while abroad.
One of the best parts of the program for me was the opportunity to meet students from other schools in the US, many of whom are still my friends today. Travelling to many different cities and locations in Spain we all became very close, and have shared memories that we brought back with us to the US.
Also, for me the home stay was an invaluable tool in practicing my Spanish with native speakers. My family was welcoming and so helpful in navigating the city and learning Spanish culture and customs.
Speaking of learning Spanish culture, one special aspect of the HCAYS is the option to take classes at a Spanish University, which some of my friends did. From what I observed, this was an additional benefit, as these friends were able to interact with peers, and create a network in the city.
Overall, I also had innumerable opportunities to try new things whether it was VERY amateur bull fighting or taking a painting class. I think Hamilton provides a unique experience and a unique opportunity to commit to learning Spanish while enjoying a small liberal arts atmosphere. I am so happy I chose to spend my junior yeat abroad, and very grateful that it was with the Hamilton Program, in fact I loved it so much I recommended it to my brother. He was in the 2010 group, so look out for his review soon.