i assume you're talking about uni of leeds?? because there are 5 unis here haha
if so, i went through this exact situation a year ago, so i know how you feel - i was torn between lcf and leeds and i chose leeds and it was the best decision i ever made. not only is the fashion scene in leeds amazing anyway, it's one of the best places in the country to be a student - massive student population, nightlife is amazing, rent is cheap, everything is generally cheap, parties on every corner, people are way more fun. the girls here are so easy to make friends with, especially in the design/media schools, and there isn't really a sense of "competition" which i've heard is very prominent at uni's like ual, as everyone is fighting for the best internships and status and whatnot. i found when i went to visit lcf it felt extremely isolated and a lot more "grown up" and i knew as soon as i got there that it wasn't the place for me, and neither was london whatsoever at this stage of my life - it's not a nice place to be a student and it definitely isn't as glamourous as it's made out to be, especially for students. after speaking to some of the girls at lcf, they did tell me they felt as though a lot of their friends were more so just acquaintances because everyone goes to uni in london to get their head down and that's it - they said it's a lot more rare for people to go out as everything is so expensive so a lot of people just stay in. the 3 years at uni are years you'll remember forever and i just wanted to have fun and not take anything TOO seriously like it is in london, and leeds is exactly that. don't get me wrong, there's a lot of work and it's extremely stressful sometimes but i know someone who went to lcf who tells me she didn't feel pushed or challenged and wished she had more work, which is something that i would of hated. leeds also has a really cool fashion society, there's a r&g fashion show each year which is incredible and takes months of planning which would also look great on a cv if you could help out with that, and the course offers some amazing work placements, i've had the best time of my life here so far and couldn't recommend it enough. also leeds is an incredible uni, extremely well respected in all fields of work, not just solely fashion - a degree from leeds would be respected from a lot of employers. if you prioritise having fun and all the other pros i've listed, if they're important to you, over maybe having more of a "mature" lifestyle then go for leeds, not saying you wouldn't have fun in london but i just can't imagine it being very fun for a student. i instantly felt at home the first time i visited campus and knew it was the right fit.
hope this helps!!!