I would check out all of the maintenance points before I switched to V-brakes. My old school Deore cantis will lock up the front and send me over the bars. Check the cables and housings. Are the cables rusted? Are the housings kinked, do they have enough lube or are they dry? If they aren't lined then they need to be greased. Are the straddle cables adjusted properly? Are the pads toed in correctly? Are the pads new or old and glazed over. Pads can be sanded to provide like new stopping power.
Most riders who complain about cantis, don't have them adjusted properly. Cantis stop very well when properly adjusted. Good luck
Tim