I'm with several others who don't like the look of them when they're deflated. They're "not my thing" but I wouldn't call them tacky.
And, as far as having multiple, it's kind of like a spectrum I think. One or two is fine... a bunch can look kind of like a mess. However, there's a house near us that has DOZENS in a small yard... and, I don't know, it kind of gets cool again when they're en masse like that. Every time you drive by, you see something new: "Oh, I hadn't seen Yoda in a Christmas Sweater before! Did you see the Minion with the gift box? Hey, look! There's Snoopy!"