In the past few months, I have written quite a few proposals. I am in a physical sciences field, and the agencies that can fund my work are the NSF, DOE, and several DOD agencies. These agencies vary greatly in how much (a panel of) external reviewers vs your program manager influence the selection of a proposal for funding.
I currently have 5 pending proposals, of which 4 were submitted in January and February. It occurred to me that, in terms of the proposal structure and PI manpower, my current batch of pending proposals does span pretty much all the different types that I have encountered so far. All of these come with different time commitment for the PI, as well as different levels of frustration and types of challenges in terms of preparation.
1) The single-investigator proposal. Obviously, by far the most work for the PI, but you have all the control over the idea, the timeline for execution, and every word and figure that makes it in. If a single-author proposal gets funded, the money is all yours, and usually there is a fair bit of flexibility in how you distribute it (again, this depends on the agency). If you get bad reviews, it's only you who sucks and there's no other way to go about it.
But, I love single investigator proposals mostly because I don't have to compromise. I compromise all the time, in all aspects of my personal and professional life, and it's nice to sometimes just have 100% my way. Ideally, I come up with an idea that excites me and then write a proposal. Excitement shows in the writing and I think it's important to convey this seductive element, as it helps your proposal find a champion on the panel. I think the best single-investigator proposals are those where you are literally in love with the project. I find they are certainly the most enjoyable ones to write, but it does sting twice as bad if the panel says negative things about your precious.
2) A collaborative proposal with another PI. I recently struck up a new collaboration with an experimental colleague from a nearby institution, and writing this proposal was the first concrete collaborative effort we have had together. I think it went well, despite the fact that we didn't have a lot of time and didn't really know each other before this. I think these can be very enjoyable to write, as you do get to share the workload, there is built-in feedback, but you presumably still have a fair bit of control over the outcome. That is, unless the other person is slightly more egomaniacal than the average academic.
For instance, in this experiment(collaborator)/theory(mois) proposal, I think we will get criticized that the theory is not a second, but more like a sixth fiddle to experiment, whereas this is supposed to be a collaborative proposal, with each institution getting the same amount of money. But, my collaborator really wanted things his way, so, since he's the lead, all I can do is defer. It's funny, I sent the collaborator a fair amount of text and a fair number of comments on what he had written; he said he had taken some of my comments into account, but it took me a long time to find which ones. I honestly thought at some point he had sent me the previous version of the text. It doesn't have to always be my way, especially in a collaboration, but when I tell you something seems unclear or is worded in a cumbersome way, trust me that I am actually saying it out of the best of intentions: I actually want our proposal to get funded. But I guess some people really like themselves and their writing. The proposal did turn our well, I have to say.
3) The small-group proposal (typically 3-6 people): I have had 2 of those in the latest batch of proposals, and these are, in my experience, the most common type of multi-investigator proposals. You end up having 2-3 people who do a lion's share of the writing, and then the rest contribute significantly less. I think the composition of the team is key for the success -- I have had successful previous proposals of this type, and it's always with people whom I know well and whose expertises complement one another. One of my currently pending proposals is a continuing grant to a DOD agency, with long-term collaborators, and I have high hopes for its renewal, as the program manager seems very favorably disposed. The second proposal turned out OK, but I cannot say I have high hopes for its funding; it was submitted to the NSF and I only know one of the co-PI's well. The PI did a very good job tying everything together, but I think the proposal does feel a touch half-baked...
4) The large-center, multi-investigator proposal (more than 10 and typically a few tens of PI's often organized into smaller subgroups of less than 10 people). These are a pain overall and really hard to get funded. The amount of text each PI contributes is fairly small, but it's really hard to make these into a coherent effort. People who are the subgroup leads are really screwed, because, in addition to herding cats, they are the ones befallen by the task of trying to get something coherent out of the hodge-podge of writeups from many various people, most of whom barely know each other.
These proposals are very difficult to put together -- months of meeting, brainstorming, inviting and disinviting PIs, trying to create a team from a group of near strangers (often several off-site people), where the people have complementary expertises, but where also people's preferences for alternative collaborators may have to be accommodated. These massive efforts are usually led by the Big Cheezes. You can actually spot a future Big Cheez (or a Big Cheez wannabe) as a person under the age of 50 who wants to take on such a monstrous task.
I am having high hopes for this batch of proposals, which I guess means I am not an entirely crusty, disillusioned, burned-out PI after all.
Happy proposal-writing trails to all!