I currently use blogspot.com as one of my blog sites. I have to say I am not impressed. While the site has some good features, a ton of templates, and tons of other blogs to follow, I have not had success with it.
I use blogs as a source of exposure that hopefully turns into income. I enjoyed the tons of different templates that they had and you could change color schemes and fonts. You could move areas of the blog around. Like the side bar order, where you want your adds and html. You could add Google Maps. So yes, if your are working on just a personal site, family oriented, or just a journal, blogspot.com works great.
However, if you want to use it as a source of income I suggest picking a site that is more professional oriented. The reason I say this is because I don't get as many views from blogspot.com as I do from some of the other sites. Not only do I not get as many views, but I don't seem to get as many followers, people willing to post comments and have conversations about my topics. These are important features in making an income online.
Overall it isn't so much that it isn't a good site, but my feelings are that it is so big that it is hard to get a ranking and a following. I feel there as so many personal blogs that many websites won't pay for your content due to not much following in the marketing niche.
So, think about what kind of blog you want and then make your decision on which blog site you are going to post on.