This is truly one of the smaller forsythias. We have it in several places and the largest, which has never been pruned in about 10 years is only about 6 feet tall. It has a lovely green and gold variegation and new stems (sometimes older ones too) are red. We have it growing in both part shade and sun. The plant will be taller in shade and stockier in sun. The variegation, not surprisingly, is more pronounced in the sun. It was sold originally as a dwarf, but small would be a better term, I think, at least as opposed to the regular forsythia.
A short word about the weather. We had a freeze last night. I haven't been out yet to see if everything got frozen - some things tolerate this quite well. In preparation we put the winter wrap back on tender things and I covered the vegetable garden where the peas, onions, lettuce, spinace and swiss chard are already up. They can take some cold, but why take chances? I also picked a large plastic bag full of daffodils that were just in bud to keep in the refrigerator and bring out a vase-ful at a time over the next few weeks, just in case we lose most of our daffodil bloom like we did last year. I also picked 2 five gallon buckets full of daffodil blooms which have filled vases in every room in the house, which is something I do anyway this time of year. I also picked some of our white lilac which was starting to open and which regularly gets frosted. Much as I hate this sort of thing in the spring, I wouldn't want to move to a year round gardening climate. Some of us, despite our love of gardening, need a little hibernation in the winter.