Investors with an interest in Engineering - R and D Services stocks have likely encountered both Aecom Technology (ACM) and Altair Engineering (ALTR) . But which of these two stocks is more attractive to value investors? We'll need to take a closer look to find out.We have found that the best way to discover great value opportunities is to pair a strong Zacks Rank with a great grade in the Value category of our Style Scores system. The proven Zacks Rank puts an emphasis on earnings estimates and estimate re ...