Ghostling wrote:i also have a prusa with chinese jhead mk IV that came with heater cartridge. it heats up super fast so it does outperform the resistor. but the resistor is way cheaper...
Cheaper in bulk and from a wholesaler.. but given they are a mis-appropriated component (they are actually just normal 'power' resistors, designed for high-power applications - the fact they dump a crap load of heat is a by-product of this process that is exploited to make them 'heaters'... but the body is not actually made to withstand this application for an extended period of time - hence their frequent and predictable inevitable failure) - its a false economy. A 'good' run will see you get 500 hours from them. Not bad for an 'improperly used' component I'll admit though ! 
Heater Cartridges on the other hand, are purpose built devices that are designed and engineered to do the task that is assigned to them. This is why they outpeform a 'standard' resistor, and also last significantly longer. Significantly. Also, thats a 6.8Ohm - the Solidoodle ones are 4.8 or 5.7 ... So they draw more current, and consequently heat faster. The 6.8Ohm ones will take marginally longer and have a shallower curve.
Having said all that - You can buy heater cartridges off of ebay.ca for as little as $5.50CAD.. delivered! Your listing is for a $1.50 resistor, +$2 Shipping... meaning its actually only $2 more expensive (not a difference I'd call 'way cheaper...'), and the moment you need to replace it more than once, its more expensive, so in reality the heater cartridge is cheaper.. anything more than once that is
) - just grab a heater-cartridge and be done with it.. less mess, no fuss.. and it'll out perform your nichrome setup anyway