Has someone here an opinion or already experience (and recommendations) with online preparation courses for writing ERC grant proposals, or for other kinds of funding?
Yes, but this is strongly dependent on the course. For example, will the teachers give you personalized feedback on your proposal, or is it simply a course that offers general guidelines and tips? Usually the "tips" type courses are helpful if you're a first-time grant applicant without a strong external network. However, if you have colleagues who have been awarded these grants or have served on review committees and are willing to look over your proposal, their feedback will be more valuable. Especially because they will be more similar to your actual reviewers (pressed for time, not in your field, etc.).
If it's a course that includes specific feedback on your proposal, or if it's a private grant preparation service, these can be more helpful because they are more tailored. I have some colleagues who run this kind of grant editing/grant preparation service, and they usually offer some statistics in their promotional materials. For example, of those whose grants went through this process, how many were funded? My colleagues' success rate is about 80% at the moment, so clearly these kinds of services can really improve your chances. However, they also require substantially more money that may not be reimbursable by your university.
I won an ERC-StG a few years ago. I worked very closely with the fundraisers at my university and found their (personalized) feedback extremely helpful. They had also managed to collect a good number of successful applications to use as references when creating my own application. Once I'd heard I got an interview, the university then sent me to a 2-day interview training course in the Netherlands (Yellow Research), which I found extremely useful. Not just for the advice they give, but because they put you in a room with 4-6 other hopeful interviewees with which to discuss and spar with.
Based on my experience, here's what I'd recommend:
- Work with the fundraisers at your institute. If they are not helpful, ask your institute to pay for outside help.
- Set aside at least 3 months full time to work on the proposal.
- Consider that some national funding agencies will offer smallish grants (something like €10k) to help support your salary while writing, or for training courses like I mentioned above.
- Find some reviewers that you trust to give you critical feedback. Some should be non-specialists in your field and very familiar with ERC grants, ideally by serving on a panel (most universities will have 1-2 current or former panel members in their faculty). Others should be specialists on your field, but not necessarily familiar with the ERC system. For this I used my collaborators.
A complementary perspective to the already good answers: Take into account how much time the course will take you, compared to how much time you spend in total on the proposal. So even if the benefit is not big, it might still be worth the time. And beyond some information, you might get to know people.