I'm in FYP right now and if you like philosophy and plan on pursuing a degree in it, my recommendation would be yes.
It's a lot of reading and easy to fall behind (last term there were sections I did less than 50% of the readings for, and I feel awful because it is totally self-sabotage. You get out of the program what you put in. Don't fall behind!!!). Essay weekends are intense, but essays aren't too long so it's manageable - especially if you have half decent time management skills, which I don't. I didn't read anything before coming and for the first section I was fine... I really just starting to fall behind when I got lazy around October/November. I think the Epic of Gilgamesh is the only one that you need to have read before school starts and it's super short. Tutorials are good, some tutors are more helpful than others but they are all really passionate about what they teach. I'm quite shy so sometimes it is hard to speak up in tutorial, especially when you hear people complaining about the people in their tutorial who talk a lot, but it's something for you work on. And that type of close interaction with professors is something you will have trouble finding at any university in Canada. I think tutorial is what really differentiates King's from other schools. It's a huge advantage and helps you form good relationships with faculty from first year. Lectures are for the most part awesome... I'm sure most of what I'm saying is what you've heard already haha.
I love the curriculum and format of the program. It's incredibly unique and ideal if you're someone who wants to explore a variety of interests all at once. I could go on for a while about how much I enjoy what I'm studying. It's hard work, but if you immerse yourself in it, it is the best academic experience a first year can get (in my opinion). My friends at bigger schools are taking intro level classes in auditoriums with 1000 people listening to a prof read off a powerpoint. It seems very impersonal and clinical compared to King's. Also, instead of textbooks we study with great works, which I think is pretty great. It's all interdisciplinary, combining philosophy with history with literature in a really natural way. Instead of reading a book that summarizes and simplifies ancient texts, we read the ancient texts. Then in lecture they are explained and analyzed, and in tutorial we discuss and question those texts further. I don't know if I'm describing it well but it's a major positive. There are some lectures where afterwards my entire way of thinking has changed. I think the faculty cares about what they teach, and it shows. Overall, very high quality program and staff.
I can't think of many bad things, academics wise, to say other than the grading, which has been mentioned. I went from being a 90+ student in high school to 60s-70s here which blows since I plan on going to grad school. You get a lot of feedback on your essays which is helpful, but the marks are lower than what I expected to get.
Now to the negatives - socially, it seems a lot like a high school type atmosphere and it is cliquey. This is especially so with the people from Toronto, who all seemed to know each other prior to coming to King's. I'm from Edmonton so i came not knowing anyone. It's so small, everything kind of gets around and there are a few main friend groups that people settle into by the end of the first month. It's caused a lot of stress for me because, being a quiet person, I was not great at bonding with people at the beginning of the year and am stuck with a lot of acquaintances but no 'friends' in January. I also hate res, maybe it's just my bay though. There are definitely parties. I know some people who go out 3x a week and some who go out once every other week. Depends who you surround yourself with. The theme parties are fun- an'toga'ne and the dante one come to mind. I think there's something special about how conversations over lunch can be students debating Descartes and Hobbes (not exaggerating this happened a lot last week) or laughing while quoting a particularly dramatic excerpt from the Bible. So there's good and bad, if you're outgoing there isn't much to worry about.
Obviously, if you know people at dal it's easy to keep in touch. And since the facilities (library, gym, sub) are shared you mingle with them often. I haven't made a lot of dal friends in my elective that I am taking there, but it's not difficult to do that if you tried. I've been to a few dal parties, either a friend of a friend invited us or we just heard about something.
There's some things that I don't like, mostly socially, and I think those things are more related to my faults than anything else so I wouldn't worry. If you're set on philosophy and deciding between FYP or taking courses at dal I 110% recommend FYP. I'm sad to be halfway done, it has flown by. I wish there were more programs like it. You can take all your classes at dal for the next 3 years and even opt to live in dal residence (maybe? I would look into that if you want to be friends with more dal people and be out of the king's 'bubble'). I strongly recommend FYP, though.