I'm also a a NYC ER guy and I'll add this. I'm a January 01 hire and can't hold a line yet. I might hold one in Dcember, I'm right on the bubble. However; I've been in this category for 6 months now and have been to my crash pad 3 times. That's mainly because we were so short of people during the summer that you were flying all the time and got your trips assigned to you the day before your reserve started. Now that things are slowing down and they are getting some bodies up here, that is obviously changing. Hard to tell what next busy season will bring. Lots of new destinations. Will we be adequately staffed? I wish I knew.
Also, to correct an earlier post. If you get short call, you don't have to come up the night before. Scheduling starts all of our short calls at 1300L. Makes since since all of our report times (except one) are afternoon, say from 1530 ish on. So as long as you can get there by 1300 (and really by 1500 because you can commute in for the first two hours of your short call per the contract) you are good.
Finally, a previous poster was right, guys love the category, but they hate commuting to reserve especially in NYC. So what you find is that every time you start getting close to a line, a new AE comes out and a bunch of guys senior to you bid into the category because now they can hold a line. So what you see is a big differece up there in seniority between line holder and reserve.
Of course the new AE that's out with the all the new categories will shake things up but your guess is as good as mine as to how it will pan out.