I've used Disney Florist a few times. Whenever I've tried to customize the order, it's been screwed up. I did the Halloween in-room celebration and asked them to switch out the types of stuffed animals that came with it. I also asked for different treats because my son is allergic to peanuts. When we got to the room, we had the standard package. I called and they happily fixed things (they had notes of what was supposed to happen). The last time, I asked for three of the "Mickey glasses" for the fireworks. We got one. I called and they said they'd send over two more pairs. We got one. I called a third time and they said they'd send the third pair. It never arrived.
The times I ordered the standard package, everything was perfect. They seem happy enough to customize when I call. There's just a disconnect between the person who takes the order and the person who fills it.