- Back when I went it was very cheap (like $60 for 2 hours, idk what it is now), assuming it went up due to very very high demand
- Notes were very in depth, I basically used the booklets as my notes for exams, didn't bother writing my own notes like I did for biology
- The questions in the booklets/in class worked through together, and included both standard questions and very tricky things they may ask so you're well prepared
- Had weekly homework that he would mark as well as practice/mock tests in class so that was helpful
- Tries to make funny jokes (good effort)
well, now I go to SIGMA
really like the material, the way it's taught is nice. also, the interaction with students by the tutor is good (and they're also very easy to interact with unlike other places i've been to)
for the other two, i dunno.
ACE booklets look pretty but 3 hour classes for physics seems a bit excessive (friend trialled and also agreed).
a ton of NSB seem to go there, i've seen a bit of the booklets but really don't know enough to judge, sorry
Personally, I would pick Sigma bc of all the perks it offers (I did online once and it is not as interactive but whoa, it still felt more interactive than other places in person and is such a nice vibe to be in bc the enthusiasm from the tutor really carries over to the student lol)
Sorry for the very late reply though