I had the same issue, trying to decide between neurosurg and ENT. There were a few things that made the decision for me.
1. I found ENT cases more interesting overall. There are a wide variety of surgical areas within ENT: facial plastics, sinus, otology, laryngology, head and neck cancer, and this means there are lots of different types of procedures.
2. Patients tend to be healthier in ENT. The head and neck cancer patients are frequently very sick, but most other surgeries are on an elective basis. This means you aren't stuck with as many ICU patients in the hospital for weeks. On many services patients go home the next day.
3. Lifestyle is better in ENT, both during residency and after. There may be exceptions to this, but overall most of the people I've met in ENT are family-oriented and do not want their life ruled by their career, unless they've deliberately chosen to do so.
4. I believe overall the people are nicer in ENT. There are surely exceptions to this and there are some great neurosurgeons, but the general attitude is friendly and cooperative...many programs I interviewed at stressed the working environment and having residents who get along well over other aspects like grades and scores. I think this says something about the values of most people in the field.
5. Most people going in to private neurosurgery practice end up doing a LOT of spine work. I did not find this appealing, and several other students I've talked to felt the same way and appreciated ENT more because of this. From what I've heard, private neurosurgeons do prodominantly spine cases with the occasional craniotomy, which wasn't what I was looking for.
6. Being specifically interested in neurosurgery as well as ENT, I was drawn to the neurotology cases. ENTs who specialize in Otology do a lot of lateral skull base stuff, such as resecting acoustic neuromas, on top of the chronic ear disease and other ear cases. Look into otology and try to see some of these cases to see if they interest that neurosurgery-liking part of you.
Hope that helps.