Pros
A really nice office in a nice location with good facilities (kitchen, break room, games room, etc) Very diverse and inclusive. The company pays for your lunch. There are frequent after work activities if you like to socialise with your colleagues.
Cons
The most toxic environment I've ever worked in. The office manager has malignant narcissistic tendancies, routinely falls out with people for next to no reason, and then goes around recruiting people into their many vendettas. The atmosphere is akin to an American high school as depicted in pop culture, with cliques of immature teenagers behaving obnoxiously and spitefully towards each other. The office is very ethnically diverse and inclusive, which are good things, but the culture of the company in general is extremely insensitive to racial issues. For example, racist jokes are seen as standard humour and no big deal. This is more of an issue with the French employees but the attitude does trickle down from France to London. The company culture regarding sexism is the same as it is with racism. I personally witnessed inappropriate behaviour and jokes directed at female staff. There's an expectation of you to participate in after work social activities whether you want to or not. It's nice that these exist but participation shouldn't be compulsory. If you stand your ground and decide not to take part, you'll quickly find yourself a subject of one of the office manager's many vendettas. You'll be gossiped about and shunned in the break room. Forcing someone to have fun is self-defeating because it's not fun if it's forced. The pay is below the market rate for most jobs.