Depends on how much risk you like to take for a supposedly "savings plan".
To most people, savings means capital preservation. If you put in $100, you must at least guarantee to get back $100 flat (ignoring inflation) even if no interest in the end.
However, nowadays, the meaning of a savings plan has just become one in which you put aside a sum of $ every month, to be invested. But as the $ is being invested, it is possible that you can make a loss. In other words, savings has become "investment".
Looking at Prudential website's Case Study illustration, I personally do not like how the Guaranteed portion of the returns is so much lower than the Total Premiums Paid. And the Non-Guaranteed portion is inflated to make the "Total Projected Amount" look attractive.
http://www.prudential.com.sg/corp/prudential_en_sg/solutions/save/PRUflexicash.html
E.g. Case study of 25 years tenure. Guaranteed portion is only about 50-60% of the total premiums paid.
In the case study of 15 years tenure, Guaranteed portion is about 70% of the total premiums paid.
Will the investment perform well so that the Non-Guaranteed amount can cover the gap to at least return you the total premiums paid?
The risk is for the buyer to decide.