Filtered deck and study session

I need to study a certain part (system) out of a huge USMLE deck.
What is the best option: a filtered deck or a study session (manually selecting tags one by one)
Also, what should I expect to happen to the cards and reviews ? Are they counted from the larger deck, am I going to see the reviews even after I finish this sub-deck or are they going to be lost ?
+Any tips on whether I should change certain settings?
Thank you in advance.