Well...I direct a charity ride so I'll chime in. I should disclaim that I've been on this forum LONG before I was working at a non-profit and directing a charity ride.
I think it matters how the event is run, specifically if it is a third-party benefit or a event solely own and operated by the charity. I'm not a fan of third-party events though we have had partnerships with them. Those are very much like licensing agreements where a portion of the profit margin go to the organization. If we can generate a few thousand dollars for minimal work...that's great for the organization, but whatever money you're paying into the event as a participant is mostly going to the for-profit event manager.
I work for a non-profit and the ride I direct is our sole property...I'm actually the person that launched the ride back in 2010 and it's my baby. We do contract out for many services and I draw a salary, so there are costs involved. The difference comes both on the expense and revenue side of things. Because of our 501c3 status, I can go to sponsors/vendors and get cash and donations that greatly offset my production cost. It is a tax write-off for them and they also get marketing ROI. My production expenses are mostly funded by sponsors, meaning that 90% of the money the participants are raising are going to the mission.
I agree with vtguy though...if you have a cause you love, write a check and ask nothing in return. Most non-profits even allow you to donate specifically to a program, specifying that your donation will not be used for administration and fundraising expenses. That obviously doesn't work for everyone or else there wouldn't be people like me.
A lot of people treat charity rides like tax-deductible vacations...they simply make the full donation and have a great time. That's all fine and good, but the person trying to get 100 donations at $25 each is doing a lot more for us because that's 200+ times they are telling people about our mission. A charity event has the dual function of being revenue AND awareness generators.
There are a lot of fun charity rides out there...many of which are so popular that they sell out very quickly. Definitely look for the ones with a good reputation.