The batch with the sugar, being more fermentable, will be drier that the batch with the extract.
However, both will be pretty dry, considering that you have used that much with only 3-gallon batches.
I consider that much headspace to be excessive, but it shouldn't be a problem while in primary, since co2 is heaviler than o2, and a protective blanket of co2 will cover the top of the cider until you disturb it.
I'm thinking that these batches, especially the dextrose one, will be VERY dry. Adding 2 more gallons of juice to each batch will help, but even then, you will have some DRY, in my opinion, cider. Way over 10% ABV as you have it now.