I have been googling and found some site on the first position of very strong keyword, and it was hosted on blogspot (it had own domain, but blogspot hosting). SO the question is: does google treat this hosting (blogspot is google's service) differently somehow? What do you think?
Can you post the blogspot blog your talking to coz I wanna check it as well. Probably it has good and quality content or perhaps it has strong backlinks ....
It depends on the content being shown in the blog... most of the time blogspot are easily being index by Google but when it comes to ranking its always been the same as others depending on the content if its very useful for users that Google think would benefit many users.
Blogger (blogspot) blogs tend to rank better just because google owns them ... so of course Google would favor them over most. You can check out a very good service over at bloggingz.com where you can get 20 miche blogger blogs for really cheap.