Hi KiKin,
I will describe SJS for you from my experience. It's been a long time since I've attended SJS - approximately 8 years, but I do know my brother is currently attending SJS and the culture usually stays the same from year to year - i.e. the same songs are taught, and so on.
Relatively recently, SJS has undergone some renovation work that has expanded the school to have more rooms etc. It shares the sports complex with SC, with the olympic-sized pool and the big indoor court. These are very good resources, if this is what you think is important!
I've found my educational experience in SJS to be good. I've had a pick-and-mix of teachers, all quite good in their own regard, and I always found SJS to have warm teachers. They have nice little traditions in assembly and they have a good reinforcement scheme (a Superstar certificate), and it left me beaming the whole week when I got one.
The curriculum itself does not focus on cantonese, or at least it didn't when I attended it. It had very good music sessions and I really enjoyed playing the recorder and all its variants. I also thought the teachers thought up very fun activities to help us understand ancient history; to this day I cannot forget all the Egyptian/Viking stuff I've learnt, nor will I ever forget the time where they made us some special naan bread. They made us roleplay characters, write out projects, do artwork ... basically, interact with our learning material in a creative way. I think SJS really developed our creative and curious minds, and I appreciate it for that.
I also still know that they encourage students to read often, implementing reading sessions and reading diaries to keep us up to date. My brother is positively a bookworm and I think that's a lot to do with the cultivation of SJS. I distinctly remember stacking up a pile of short chapter books in my time and reading through them all in one sitting!
The homework is not strenuous. When I attended, it strongly focused on parent-child bonding, handing out parent sheets that they would have to hand out to evaluate how well the child did the homework. Ah yes - I remember the school advocated a lot of self-evaluation, and asked us to rate what we could do to improve and so on. It was more quality based and introspective, pushing us to improve ourselves by our own basis.
My brother is blossoming well under the education, I find. His reading of English is exceptional for his age (well, in my opinion anyway) and we have high hopes for him. I'm glad SJS reinforced our love for literature, and I still adore it today! However, that just might have to do with our family on the whole rather than the institution itself, but you never know ...
Hope this helps! Good luck!