Hi! Sutton Trust Alum here!
I was part of Cohort 11 of the programme, applied on a whim, and I can safely say that was the best decision I've ever made! As I write this, I am most of the way through my first semester at a US university, and I could not be happier! I could never have even dreamed of such an opportunity without the amazing work of the Sutton Trust Programme.
Having both gone through and then worked on the Programme as a graduate, I have always been in awe of how amazing the experience truly is! The programme is so much more than just an academic program like UNIQ, it is a once-in-a-lifetime experience that truly made me grow and change as a person, as well as allowed me to develop skills that I use all the time in university life! The support network of both peers and the Sutton Trust team is the perfect springboard towards higher education in general, as even those who attended UK universities from my cohort still thank the programme for the skills they learned and the connections they made throughout their time! It is also extremely fun; I've literally made friends for life in both the UK and the US, and have so many amazing memories... and my cohort didn't even get the US trip! (I did go on this last year working on the programme, and it is truly an unmissable opportunity!)
As for application tips, I would really recommend that you tune in to the upcoming applicant webinars on the YouTube channel in the next few weeks, as both staff and alum will give detailed advice on filling it out. It really is less scary than it looks! My biggest piece of advice would be to take your time. I literally started my application the first day they opened, and submitted it with 11 hours to go! This amount of time is a little excessive, but the application is so much about getting to know you, and the more of yourself you can show through your answers, the better your application will be! As for the video interviews, I watched a lot of the ones available on YouTube, but please be cautious that some of these do not meet the application guidelines and you have no idea if these applicants were successful. It's a great tool for getting a creative sense of the kind of things you could do with your video (everything from a retro Draw My Life to a Powerpoint presentation to a mini personal documentary to just a sit down chat with the camera) and the kind of content you may want to include, but aside from that, trust your own skills! The programme staff don't want to admit another person, they want to admit you at the end of the day, so make sure your application is as 100% you as possible. This process is modelled on the real Common Application process for US universities that you would go through on Part 2, so it is also a super helpful training exercise for that!
I hope this helped. If you'd like more information, you can reply to this comment and I'll try to answer anything I can!