Recognazible rootstock due his typically red leaves and red coloured wood on the surface.
The Budagovksy 9 has been tested widely and is used commercially in several colder places in the world. In general it is a bit more vigourous than the M.9 and has potential for lower densities and low vigour conditions.
The B.9 is a valuable, precocious dwarfing rootstock who is more winter hardy and a bit more drought resitance than a regular M9 clone.