I am a relatively senior bus fo and live an hour from the airport. I bid reserve occasionally (not during summer) and try to hide. I think the most days I have worked on reserve has been 10. One month was 4. My lines typically have 17 days off. It all depends on the staffing. If it looks like they will be short then I will bid a line. To me bidding reserve can be great if it's a choice. If you bid into a situation where you be on reserve for long period of time it will be not so fun.