York, I planted three MP for a hedge and have been pleased with them. The blooms don't do brown goo, if that's what you mean. I sometimes deadhead but I don't think it's necessary; the dead blooms eventually fall. I don't think they're ugly either, as they brown and drop. It's a nice rose.

It probably depends on climate or which MP you get. There a two different forms going around one is significantly more double than another. I had a more double MP in my garden and fowers stayed on the bush turning brown. It was not looking good to my eyes, so I always had to deadhead it.
I expect it will require spraying in MA,at least when I lived in CT I had to spray it to keep BS off, the same here in MD. Looks like it is more resistant in Southern states. Usually East part of the country reports about its being a healthy rose are coming from TX, SC, etc.
Olga

Olga's assessment of its health would be much more accurate for east coast conditions; I actually didn't have any kind of an opinion of its health at all. It's been fine so far for me, but they're young plants and I don't think bs pressure here is very bad.

I was just trying to say that the blooms don't turn to brown mush like Mme. Plantier's do when they get wet. I don't consistently deadhead them because I don't mind how they look, but YMMV, and I would guess Olga is a more fastidious gardener than yours truly.

Marie was free from mildew in Pacific Palisades (two blocks from the water) and here in Encino on the ridge top. No black spot or rust, either. Dead heading is mainly for shaping the plant to remove the super structures of the spent flowers so they don't look like the skeletons most polys project when flowering. Here, she is shade tolerant, extremely clean, very free flowering and marvelously fragrant. A very satisfying rose in all regards.

Everyone seems to love this rose. Not me. I just SPed all my Marie Pavies -- about 6 in all -- because those papery brown blooms just wouldn't release. The dead blossoms weren't soggy, but the plants were always a messy mix of pretty white blooms and over the hill brown ones. Unless I deadheaded them almost daily, they looked awful. And because of the numerous small blooms -- a good thing, in theory -- deadheading took forever. In the end, it just wasn't worth it. They were still very healthy, so I pulled them up and donated them to the local plant bank.

I have several Marie Pavie and I love them. The scent is sweet and wonderful and the foliage is very healthy. I have never sprayed this rose. As long as there is adequate water this is a great rose. Blooms all the time. Now (we've just had a hard frost) there are certainly unsightly brown flowers on my plants, but Marie Pavie blooms early, late and much for me and quickly covers old flowers with new. Deadheading is great if you have time, but the problem is not a big one and I rarely worry about it. Mine is the more double version too. :) I tend to pick huge rose varieties and Marie Pavie has been so helpful to fill in around the larger plants.

I had the less petaled version in Alabama but bought Vintage's clone, more double, this time. I really like the more heavily petaled blooms from that clone. :)