I play manual targeting with map updates (because it is the fire control teams job to assist me in this). I estimate range usually using an active ping (if not escorted) and speed based on trig (which I learned in college). Actually what I do is less complicated than most trig anyways since I tend to use
Law of Sines,
Law of Cosines, and sometimes
triangulation. When I feel really lazy I tend to stick to the fast-90 method. After a year off subsims I was greatful that there was something like Travelly's tutorials to remind which controls do what on the U-Boat.