Yes, I'm a product of SK then SMK then international.

I can give you my long testimony on what I enjoyed the best from both worlds.

Yes, because school is another form of business entity.

Yes, more freedom in terms of discipline.. especially handphone, laptop, tablets, hair color, length of hair.

So long students do wear official school uniform its fine, they won't make so much noise.

At the end, school do their part, parents would need carry out their duties as well. So if you send your kids late = your problem if your kids cannot adapt later stages.
The final examination is IGCSE so papers are provided from the official institution so even you complain essay work, etc you still cannot run from facing the official exams and students are well aware of that.
I don't know how to justify if I am a better quality. Imho, I did have a better balance of friends. Higher net worth friends end up carrying out business for their parents, one even invited me to their wedding (both my classmates) this month. So young get married.

I did mine from SK 1-6 then Form 1. Most friends from SK went to the same SMK, did have a lot of friends in SMK since there are so many classrooms, each with 30-38 average students. I moved to intl nearing the end of Form 1, graduated 1 year earlier than my friends in SMK.

The quality of education really depends on your kids discipline and his/her circle of friends. The syllabus will be slightly tailored towards whatever exam your kids are taking, mine was IGCSE so I received British textbooks and followed the same syllabus as them. I entered intl in Year 9 (should be equivalent to Form3) so I had to learn add maths and those science subjects. When picking the school for your children I think you should do a little research as well as to what year he/she might enter .. what's the difference in the syllabus with a government school.

If you asked me what's the biggest contrast with government school, students are expected to copy down notes in books and then memorize them (potentially). Whilst, some teachers in intl can be very 'extra'.. walking into class, turn on ppt and lecture the whole way for 2 hours. You can either jot down notes or type them into your computer. The first lesson will always be a lecture about the topic then follow by tutorials or something interactive later on. By 2/3rd week teachers will handout assignments and expect you to complete in week 5/6. This applies to other subjects as well sometimes date may clash in a week where you have a lot of deadlines when exams are in the corner. That's when parents come in to complain about this and that .. lol (usually that's the case people generalized about international school students are strawberry generation). Later stage of my life entering to college then uni .. this is the same process, lecture, tutorials, assignments, exams. It's not hard to adapt especially started earlier than government school students how to do research, formulate discussion, referencing and presentation. Yes, it is silly when you're graded for presentation (sometimes they grade the way you speak, etc).

Finally, the best part, going on trips! I love it but some parents would disagree with their kids going on trips because of 'virus, people died in the sea, air pollution' when the school decides to go places like Beijing, Bali, etc... and usually parents voiced out their disappointment because they are expected to fork out RM3000,4000 per year for extra trips. Luckily parents didn't question much since they are okay, I went to Bali, Beijing, Hangzhou, Suzhou, Sarawak (volunteering to clean orang Asli house, free labor). Why it is the best? I get to meet new friends from different campuses from different states. Every trip about 130+ students and every year see different faces or same ones... best lah so many memories everywhere we went. Later also, same time uni and go to different countries end up meeting them for lunch/dinner occasionally (usually i only lunch with amois, also grow up beautiful liao  ).

The bad side of international school = weed, drugs. Whoever the dealer makes shit tons of money because they are willing to pay for whatever the price, no sense of appreciation towards money?? I don't know. Also, the wrong circle of friends = gone case... cheong starting at 15 y/o. I guess you can't blame entirely on school, friends and etc since also part of duty as parents to be aware of children's activity. It wouldn't be fair to the school, sometimes they can't shut it down completely, worst-case scenario expulsion and the bad apple will just proceed to the next international school to start such culture. There are cases that happened but silenced out completely since no police report to be made that will tarnish school image and parents' background... things like this don't happen maybe once or twice a year for special students.
Edit #1
I typed until here forget to tell you the best side about public school as well. Friends in public school best, helps bringing you at your feet because they represent the average working class of Malaysian. Seeing your friends in private school spending on food, shopping, or the latest gadget may be difficult for a student, especially girlfriends all already carry Chanel, Hermes... then boys... Lolek, Patek, Ap... living the dream at that age yo! As I mentioned, public school friends will help you stay on your feet because of some high achievers will always challenge you to stay competitive, thats for me. If he can enter into unis like Imperial College, Oxford through his hard work, then you should do something about yourself as well. They don't need materials to flaunt, reflecting a hardworking culture. Government school friends some also follow parents business or joined Big 4 and good MNCs.. not too bad themselves.

Education? I guess sometimes teachers may be young + rotating from different states / passive-aggressive/aggressive methodology - you get funny responses as student. I'm afraid of some teachers who goes ape shit in class and couldn't care less about teachers who don't have passion/effort in their teaching.. especially those who read from a textbook the whole 1 1/2 hours.

Good ? Better sports activity, facilities such as tennis, badminton, pingpong, track, football, cricket, etc etc.
+ Cheap canteen food... in intl school the prices are rip off. SMK average daily food prices 6/7. Intl average daily food price 10-15.