Canaccord's Bobby Burleson starts coverage on ExOne (XONE +5.6%) with a Buy and $55 PT: he sees the 3D printer maker benefiting from the adoption of new materials such as titanium, and sees long-term growth fueled by the migration of industrial clients "from low-unit-volume evaluation phase to higher-unit-volume production," as well as by rising production service center use. SA Pro contributor Brian Smith, Jr. recently offered a more bearish take. 3D printer vendors are once more moving as a group: DDD +3%. SSYS +1.6%. Though clocked last month thanks to a Q1 miss and light guidance, ExOne is still up 150% from its Feb. IPO price of $18.