The key thing with saving plans are that you want your capital to be guaranteed. However, there are saving plans that actually do not guarantee your capital fully.
So do look through the Benefits Illustration table, see if the guaranteed portion fully matches with the premiums you pay. If a saving plan can't even guarantee your principal capital, ditch it. Some endowment plans actually offer you some guaranteed interest alongside your principal eg. AIA Smart Wealth Builder so thats something you'll want to look at too.
Also, which saving plan will depend on your objectives and time horizon. Are you looking to meet a long term need? Do you want to appoint your child to take over this plan in the future so that your plan can keep rolling? These are key things you'll need to answer before opting which one to choose. Do make sure you are comfortable with the time horizon as well and it meets your particular objective because some plans do have quite a long lock in period in which you are unable to withdraw your money partially without incurring a penalty.
Financial planning is an integral part of life. You can reach me here to find out more.