What are the pros and cons of the Old English mastiff?

What about health concerns? Life span? yes, they're said to have an average life expectancy of under 10 years, but what if its a healthy pup and well taken care of, can they not life beyond that? I'd love to know about this! Also, how trainable are they? supposedly stubborn, but that means its impossible!? or that not much can be done? And moreover, how well do they do with other dogs? with respect to this, let me say i have a 11year old labrador, and I have also had a great dane before, no problems between the two before, as a matter of fact they formed a team! So, i kindly request as much information imparted as possible on this question in general, especially the three questions i mentioned in specific! Yea, google is there, but i need information from personal experience of those who own/have owned these goliaths!