If you use the minimum 2.5 daily vacation credit that means the scheduled vacation will burn less from your user/vacation banks, but it also means PBS will have to give you more flying to meet your credit target. You can always try to bid a lower monthly credit, but that only works if it's a light month and other pilots try to bid higher credit.

If you use a higher vacation burn, that will make the rest of the month easier but of course deplete your bank faster.

I always use 2.5, to maximize the time off which I can schedule far in advance vs hoping for some days off in the bid, which may or may not be where I want them.

Also...you guys know you can also use user time for vacation, right? You just have to not blow it all on sick calls, missed commutes, etc.