Engine wise no issues at all. I had to change front shocks, that was because the old shocks were finished. Though atm its not the original shocks but I reckon the original will work just fine as well.
Have faced the breaking issue but that I am guessing is because of my faulty T atleast that's what I know its called so at high speeds breaking very hard won't yield the desired results, [I](but that is specific to my car).
[/I]If you drive aggressive then you'll have to change your tires as well, (this will improve breaking and grip) I've 13" tires and if I accelerate hard in 1st gear then they skid and this happens is 2nd gear as well the engine delivers too much power and 13" are not enough to handle that amount. Still running 13" though as I don't push the car on every signal and drive calmly most of the time.
But if you don't want to have a really fast car then you should go with the overhaul a proper one as the G10 is not underpowered by any means and from what I've heard if maintained properly gives pretty good mileage as well.