It will be no secret to my readers that I do work that is on the outer fringes of what NIH funds. I would consider NSF to be the main funding body I can submit to, but like any forward looking individual, I've moved in various directions that allow me some funding flexibility. Given that I am within a stone's throw of an NIH institute or two, I have lobbed a few forays their way in the form of an R15s (A0 and A1 revision) and an R01 (pending). Surprisingly, I got damn close to the funding line with that A1, despite the A0 being triaged. I also have no idea how the R01 will fair in a few months.
I sent in the R01 because, in repeated discussions around the bloggosphere (I'm too lazy at this hour to track down all the links from Drugmonkey et al.), the general consensus is not to waste your ESI/NI status* on a capped budget like an R15 or R21. Fair enough, why use your one time advantage on $300K total in direct funds over three years when you could be using it to pull in an R01 at $250K/year in direct for five years. Massive difference, right?
But here's where it's different being the square peg in a round hole world. Unlike a lot of people whose work is right in NIH's wheelhouse, I could spend a career chasing the pot `o gold at the end of the R01 rainbow only to realize that it is always just beyond my grasp. The average age of a new investigator R01 for people doing NIH science is around 42 (NIH ppt), which is almost a decade older than I am right now. So do I bang away at the R01 or assess my situation differently? Perhaps realistically.
R15 funding is along the lines of an NSF grant, though on the low side. But landing a couple of R15s to go with our NSF funding would be a Very Good Thing. Would an R01 be better? Of course, but if the odds are much longer**, why not shoot for the attainable now in order to establish myself before aiming for the big one? I need cash now, not in a decade, and the R15 funding rates are higher than the R01s. I can do a lot of damage even at $100K/year. Certainly more than I can do at $0K/year.
And so I go back and forth on this issue all the time on what strategy is going to work for me, at my institution with my resources, expectations and doing the NIH-fringe science I do. If I can "launch" with R15-sized funding in the next few years, do I focus on getting that or keep my hand in the R01 pond? Amazingly, me ceiling at 2:00 am doesn't have the answers.
*ESI = Early Stage Investigator, which gives you a bump in fundable score for ten years post PhD.
**Whether or not the R15s are judged with the expectations of an R01 is an area of debate and I get the impression this is study section dependent.