Piper Jaffray analyst Troy Jensen says his firm's 3D printing survey once again indicated system demand remained challenged in the March quarter. A number of the 68 3D printing resellers indicated the quarter came in below plan, "significantly" outnumbering the resellers that indicated Q1 was above expectations, Jensen tells investors in a research note. Many sellers stated that demand was "extremely challenging" during the month of January, the analyst adds. Jensen is still confident that 3D printing demand will improve in the second half of 2016, and continues to prefer Stratasys (SSYS) over 3D Systems (DDD). He believes, however, that Q1 results could be below consensus expectations.