I would not know if TF has a lower capacity than Spidey, but the thing to remember about the lifts is that there are two of them. I just think by having two, they are not a factor in slowing the dispatch time between vehicles.
I had a TM tell me TF was more efficient, but that could mean anything...for example, not having fire brings down operational cost...anyway, I did not time anything, but on my last trip, riding Spidey not long after riding TF, I felt they got guest loaded and on their way quicker on Transformers....just a gut feeling...anyway, the TMs on TF do have a sense of urgency to get guest loaded and rolling out...