Ours is 7 yrs old. I used to see Newfies all the time when vacationing in NH as a young girl and fell in love them. I talked my DH into getting Mac after we did a lot of research on them. There are farms in PA that breed them, but these farms are not reputable and the pups end up w/ LOTS of problems. So we had Mac flown in from Wisconsin from a very reputable breeder and his parents were both show dogs and their pictures were all over the Newf mags.
I totally agree w/ everything mom2of2 said. He really doesn't eat a lot.... 2 cups in water in the morning and evening... that's it. I did not do a training school, but I did have lots of time and I worked very hard on training him myself. He came to work w/ us and I brushed him every day to get him used to it and worked w/ him on waiting until I say "o.k." to eat his dinner. When I fill his dish, he will still wait until I tell him "o.k." A couple of times we forgot to say that word, and 20 min later we heard him barking from the garage. We went out to find him looking into his bowl. We felt so bad. He had to be held down a couple times to show him who top dog is, but now that he is 7, we have no issues w/ him at all and no aggression whatsoever. But we did have to keep up w/ him as a teen though. They can overpower you if you are not careful to train them well.
We wanted a Newfie because we didn't have kids yet, and wanted a dog who wouldn't snap at the kids. He is WONDERFUL w/ them. So gentle and loving and wants to be w/ us all the time. We lived in an townhome for a while w/ him, and people would think that was mistreating him. But Newfies have a low metabolism, sleep a lot, and don't mind small spaces. They are not runners. We got a male because Newfie males are BIGGER and known to stick around the house more, unlike other breeds. It's the females that will explore and leave the area. He wanders, but always stays close to home. We live in the mtns and hike w/ him and he stays close by and keeps his eye on the kids. I heard the dog in Peter Pan is actually not a St. Bernard in the real story, but a Newfie. One time grandma couldn't keep up w/ our toddler, 2 at the time, and she cried out. Mac took off after him sensing the danger. I ran around the house because we have a pond back there and there was Mac, right beside Tristan watching over him. I felt so relieved to have him and he is worth every penny. I never saw Mac run so fast in his life, but when needed, he's there.
Cons....... Drool. We have more of a tight mouthed Newfie and he's not so bad. Dry mouth is to be avoided though. We have no Hip problems yet but that is an issue and bloating is an issue w/ long dogs like Newfies and German Shepards. He doesn't bark much which is great. I think a thief would have a hard time getting in because Mac lies in front of our door and is 170 lbs. But if anyone comes into the house, Mac will greet them nicely w/ no signs of aggression... that is if he is awake. Otherwise he'll sleep through the visit. But he is intimidating. When we took him to Baltimore and walked back to our car w/ him on a leash, people actually stood up off the store stoops when he went by out of fear and respect. He also has horrible allergies. He is supposed to be in Wisconsin or another such cold state, and we brought him to PA. The warmth and the pollen nearly killed him and we had to take him to Baltimore for an analysis. Now I give him shots and allergy meds and he is much better and is gaining his weight back. Tons of hair.. I must vacuum all the time. We used to have tumbleweeds floating thru the house. But w/ kiddies crawling around, Mac is now sequestered to the Mud room or outside. Another problem we had was the marks on the walls. We moved into our new house and he would lie close to the wall. His fur is oily and black and puts black smudge marks all over the walls. Then he'd fall asleep, roll onto his back w/ his paws in the air, and scratch the walls w/ his nails, like waist high. So he is very rough on the house itself, but not intentionally. They are not vindictive or destructive in the sense where they chew shoes or couches. Nothing to that degree. When he was young, we had a difficult time keeping him from jumping on people, he was so excited. But now he just wanders around calmly. There is a mean dog in the area who scares me when he comes up to me and the children, but Mac waltzes over to him (playfully) and the other dog runs w/ his tail between his legs. So even though Mac shows no meanness, other animals are frightened of him. We live in the woods, close to state game lands, and we have a bear running around up here and other animals and I feel good having Mac around. But we must keep him in the house during hunting season like the other poster mentioned. He has never tinkled on our furniture or walls, and holds himself from 6 AM until 7 PM on occasions where we couldn't get to him in time and no accidents. He has set off our alarm once or twice when we left cookies on the stove to cool. He just puts his front paws on the stove and gets them, knocking the pan down and setting off the alarm. He also goes through the garbage if you don't get rid of it. He has eaten lobster shells and other such yucky items when we leave him unattended w/ a garbage bag. But we can lay a baby gate (not latched into the wall) across the mudroom door and he won't knock it down. When the gates not up, he will not cross the doorway from the mudroom into the kitchen unless we call for him. Newfies are not highly intelligent like German Shepards, but like retrievers, they are so willing to please and so learn very quickly to make you happy.
Lastly, he is wonderful. He is calm, gentle, loving, lets us brush and trim him for 4 hours at a clip (but we must brush him and trim him for four hours at a clip), he waits for the signal to eat, protects us and is wonderful w/ 2 little kids pulling at him. He is extremely high maintenance, but is worth every single minute. He doesn't cost us a lot on food, but we spend a good $500 a year on medical for him because of his skin condition and he must take double of everything like heartworm meds. We had to invest in a tub (he sits there beautifully letting us wash him) and a razor so we could trim him ourselves. He is a lot of hard work, more than the kids, but I wouldn't give him up for a second. Newfies have webbed feet and love the water. If you have a pond or water nearby, they are in heaven. We'd love to get a 2nd one, but I don't have the time to train him as I did w/ Mac now that I have 2 kids. But Mac is part of the family and we wouldn't be the same w/o him. Hope this answers some of your questions. Here's a picture of him. It's the only one I had on Image Station, but it gives you an idea of his size. They take really great pictures in the snow!!!