I brewed a standard porter a couple months ago, but my Wyeast smack pack didn't take off, so I added the only other yeast I had around at the time, which happened to be Montrachet. After three weeks in primary, I kegged it at 1.015, and kept the keg in my conditioning closet for another three weeks after purging the oxygen. I pulled the pressure release valve every day or two, and gas came out every time, so the yeast was still at work. After chilling and carbonating, I tasted it a few days ago.
It tastes pretty dry to me, but it's a pleasant beer overall. Grain notes are restrained, but there's a touch of roast. Not getting the fruitiness of an ale yeast, instead there's an interesting tartness. It turned out better than expected. It's also young, so I'm looking forward to continued tasting.
I didn't get any cidery or rubbery flavors, so I'm not sure what might have caused that in other beers. Using wine yeast in beer seems to be really hit or miss. Anyone have any further tidbits or knowledge to add? My experience was positive, overall, and it makes me want to brew more beers with unusual yeast strains.