Currently I'm cutting; I do 4 weighted workouts per week, and 2 'conditioning' days. On the conditioning days I'm at about 15g net carbs. When I'm done cutting and am at a maintenance phase, is there any advantage/disadvantage to continuing to do this on conditioning days?
There are both advantages and disadvantages, depending on your goals. I personally like to bring CHO (carbs) up to moderate levels when doing maintenance. This will help recovery and anabolism, but of course will blunt some of the fat burning effects.