I just wanted to know more about them. I know that they have a reputation as being pretty gentle desite their size and being a good dog to watch the house although they don't generally attack intruders. I mostly just want to know about maintenance, etc

http://www.bullmastiffinfo.org/maintena.htm :P

I have never owned one but do know that sum have eye problems(ie Cataracts/Macroblepharon[think that is how it is spelled had to google to get the actual name]) and hip(ie Hip Dysplasia) problems which can get pretty bad as they get older.

my friend has 2 of them.

as far as the attacking intruders goes iv seen her female chase bears out of her yard more then once

but iv never seen her male chase anything (never seen him do anything but sleep and eat lololol)

not suprising, arent they huge dogs?
however i want one that could spook a bear XD

I have a bull mastiff.

All my dogs have always been loving and affectionate, as long as you treat an animal well they will return it.

They are big and cost a lot to feed.

Mine is highly protective of me and is great with children.

If you have the time,space and money they are a great choice.

they are HUGE. only problem with that is the bigger the dog, shorter the life