In february, my wife and i spent 8 days at hostel columbus, right in front of "the jewel of san jose", the la sabana park and about a 20 minutes walk to downtown san jose, using the paseo colon avenue.
This is the second time we have stayed there; last year we also did and came back because of the many pluses this hostel has to offer:
the perfect location, the nice rooms with king size beds, the greatest free breakfast you can ever have and the magnificent relationship you reach with the owner who is a south korean-costa rican guy.
I really appreciate the friendship i have achieved with teksu, the owner, a great guy who is at the hostel/korean restaurant 24/7. you can see him all day and night working and ready to help you.
And, the price for the rooms is better than any of the hostels around the area.
I fully recommend the hostel for any number of days you want to spend in san jose.