The hugest advantage is not having to manage all of that music on all the machines in our house. We just have one backup somewhere in case we need it, and then everyone syncs with iTunes Match just the music they want on their personal device.
I have no trouble with playback on iOS. But I don't tend to stream, I tend to sync the songs I want to the device and then play them.
The one time I did have problems with iTunes match was a period where we rented a house in rural mexico. We were using some sort of fly-by-nite mexican ISP, and iTunes match had a lot of difficulty. It was really inconsistent and it sounds like this is what you experienced.
I suspect the issue there is that certain ports were being blocked, or that the ISP couldn't keep a consistent connection (Though loading web pages was fine, longer streaming connections like watching video were not.) I think iTunes match is probably sensitive to needing specific ports open and isn't great at falling back when they are blocked, or isn't great at handling frequent interruptions in the net connection (even if they are short.)