Quote from ProfLogic:
...Tick charts are more accurate that Minute charts because they are based on a specific number of transactions per bar but a transaction can be one contract or 300 contracts. Perfection is a "Contract" or "Volume" Bar where each bar is made up of a specific and perfect number of contracts traded.
Have you found the perfect data feed? One that give you EVERY SINGLE trade so that your "volume" bars are a perfect reflection of EXACTLY what was traded?
If not, now what?