I own both and owned a LOTR for eight years......GOT playes nothing like LOTR (which is a good thing). GOT is IM fast without the brutality. So while ball times are longer than IM they are nowhere near LOTR long. Another way of putting it is on a scale from one to ten (one being the shortest ball times) IM is a one, LOTR is a ten and GOT would be a four.
BTW I would have recommended IM for you. No pin is as intense as IM and having it with some other longer ball time games is awesome. Great music great call outs and it fights back!