remember, in a comp you will have to hold the bar steady on the chest until it is deemed motionless, then drive up on comand. Not like a BB lift at all. Make sure you practice these. Also you will not have a center spotter after take out of the weight. Factor in nerves and a different bench than your used to. All these things can have a major difference to your lifting.

My recomendation would be that no matter what way you build your power be it dumbells or bar, make sure you practice the conmpetition syle of lifting. P.s. if you can get hold of a hammer strength bench machine these are very good for the drve off the chest