Before I give you guys direct answer why term loan is much better, here are 2 examples for you guys to discuss.
Mr. A had taken a $100k term loan @ 5% for 30 years.
He has $100k cash and re-invest it, the return is 10% per year.

Mr. B had taken a $100k flexi loan @ 5% for 30 years.
He has $100k cash and park it in his flexi account, thus cancelling his interest payment.

Both of them use their $100k for monthly re-payment.
Who is richer after 30 years?

Actually, it pretty simple. If u have an investment with returns BETTER than what the bank charge u, then use your excess cash for investment. Otherwise, dump all the excess cash into the flexi loan .....as simple as that! However, u have to evaluate the risk-return of your investment. Investment being investment, it has risk! High risk, high return. A lot of people just want to get rich fast end up losing all their money. Invest in an instruments that your are familiar with.

For me, I am a risk adverse person. I park most of my money in the flexi loan. Unless I am very sure of the investment, I will not touch it. I invest on a bigger cycle i.e. during recession meaning now where everything is cheap. I will sell when times are good. U only need to invest a few times in your whole life.

Just my 2 cents