F2p level 35 player here. I got like 15k trophies with both N slayers (didn't have any event gacha tickets until much later; just decided to save them for the next event). This was my first Gambit, and I just barely got to room 200 with some of my peronamin (after using all of my shakes). It is a killer event for me; I was jumping on every possible moment to use up my stamina (about 200 max). I thought I might be able to get top 1000 for the SR card, but ended up somewhere around 1300-1500
I did decently well in the Coliseum, despite having just started playing at the beginning of the event. At least I could get the consecutive victories awards without too much of an issue (faced the lowest rank Babe opponents with a Sexy R team and a lvl 100 SR Babe), and I made top 1000 (I think) for the second half in victories. Then again, that was a bit more balanced because everyone has the same amount of focus, as opposed to stamina. But I was very disappointed that I had to really bust my butt to get anywhere near decent rewards in this one. I only hope that the Elite Guard is more forgiving than this.