Midcap mutual funds have historically provided superior long-term returns for SIP investors compared to smallcap funds. Over 10 and 15-year periods, the Nifty Midcap 150 TRI outperformed the Nifty Smallcap 250 TRI, showcasing better risk-adjusted returns and stronger business fundamentals. Despite trading at a premium, midcaps exhibit greater stability and lower drawdowns than their smallcap counterparts.