New World on Victoria Park, north of Finch has push carts. They are not bad, not great either. The thing is, no place the uses carts are going to have realy good dim sum, every single place that serves good dim sum will be ordering off the sheets nowadays.
There is one at Yonge & Steeles which used to be called Furama. They've changed owners (dont' remember the new name) but still offer dim sum in carts. On the dim sum tasty scale, it's about average.