The Plant Science Dept. of the Nova Scotia Agriculture College evaluated 58 English Roses to assess their hardiness and disease-resistance. Their results can be found at: http://www.nsac.ns.ca/nsac/ps/annual96/mapple.htm. Jayne Austin
was found to be reasonably tolerant to blackspot.
According to the New Zealand Plant Variety Rights (PVR) web page, application for a PVR Grant for this rose was made November 24, 1992 and granted May 23, 1994 (PVR Grant No. 855). The breeder's Reference for this rose is Ausbreak. The New Zealand Trade Name is 'Jayne Austin'. This PVR Grant expires May 23, 2017.
Here's some input from someone who grows 'Jayne Austin' in Texas: The height listed for Jayne Austin is accurate for those areas which have short growing seasons. In climates such as San Antonio, Texas (where I live), it can get five to seven feet tall. The shape of the bush, which in my garden was tall and arching, nonetheless allowed it to fit into a space for which it might otherwise have been too small. It is also reasonably winter hardy, and the fragrance is wonderful.