Got the hang of it thanks 
Am I right in saying that if the weights too heavy you'll find yourself dipping lower in order to get your wrists under the bar? and thus this will affect the smoothness of the motion or possibly stop the bars movement and then start it again as you finish the rep with your legs?
I'm not particulary good at exploding from the bottom! perhaps jump squats could be something to consider.

Am I right in saying that if the weights too heavy you'll find yourself dipping lower in order to get your wrists under the bar? and thus this will affect the smoothness of the motion or possibly stop the bars movement and then start it again as you finish the rep with your legs?
I'm not particulary good at exploding from the bottom! perhaps jump squats could be something to consider.