Hello Alon!!
I'm from Valencia I recommend you to stay in a short term apartment in Valencia (we have beach and the city is very alive and cultural).
We have very nice spanish accent and Valencia people are used to foreing people and very helpful.
Valencia is plenty of good academys of spanish. check espanole.es but we have many others.
I recommend Valencia Flats for shor term rental apartmens because they have more than 12 buildings to choose in the best city areas.
I went at a very good school in Barcelona called Barna House where all the teachers are native. You can taKe a look at this website: http://barnahouse.com/index.php/en.html
Salamanca, (google this) Colegio Delibes
I'm going over many sites and trying to get an idea which school will be the best for me. I'm in a level of intermediate.
I would like to study spanish for 2 weeks in a nice place that will be not too expensive and will offer quality teachers, materials and methods of teaching. I'm thinking about staying in an apartment and not with a family.
activities look to me like a nice extra. I understand that some of the schools charge for those.
I still didn't decide if it will be the big city (Madrid), Salamanca or any other option where I can also communicate with the locals.
so please help me... and personal experience is a bonus :)
thanks!
Alon