FYI from
Poliquin Performance Center 
Question: Should one pause the bar at the bottom or bounce the bar between reps of power cleans or power snatches?
Answer: There is a difference of opinion amongst strength coaches regarding which approach is best.
I prefer the first technique where the bar momentarily pauses on the floor before the next concentric portion because it overloads the posterior chain far better. It also allows one to recruit higher threshold motor units, hence leading to better strength gains both in terms of rate and magnitude.
The ones who use the bouncing approach usually do so because they have a weak lower back. They use the elastic component inherent to bumper plates to help gain momentum in the portion of the range where they are weakest: the bottom position. Every single athlete who learned this approach always turned out to have a lower back that limited their performance.
Pausing between reps also provides a better quality strength and power stimulus as it forces you to overcome inertia on every rep, even though the load on the bar may be lower than what you use with the bouncing approach.
Very few strength coaches realize the importance of training the lower back in the bottom position of pulling from the floor. Increasing strength and power in that range is what has the most carry-over to improving power for the first two steps of any expression of sprinting speed whether it is for soccer, rugby or bobsleigh.
Lastly, pausing between reps is also a much safer approach for the spinal column.
Stick to the full range, pausing between reps. You'll be rewarded with greater strength gains and a healthy spine.