In the end, the choice between direct and regular plans would depend on your individual investment savviness and your ability to navigate the long journey towards your financial goal achievement without support of an expert. Investing patterns studied over several years suggest that investors who remain invested and meet goals Vs investors who redeem mid way the difference often is an investment expert by your side. Unassisted investors end up getting 1/3rd the return in the long run as per a recent JP Morgan study.
Large investors often negotiate fees with their chosen advisors who then help them invest in direct plans. However, if the investment amount is less than 3-4 Cr the economies of scale favour investors who take help from an expert and invest in regular plans.
Direct mutual funds have been wrongly interpreted by many as a way to avoid professional advice. Nothing could be more detrimental. Professional advice is a must and the cost of the same can be negotiated depending on the investment volume.