Hiya [USER=37426]@tarty23[/USER]
Just building on what's already been said, I agree that there's no real right/wrong answer here. Given the limited word count, it’s usually more effective to focus on one, or at most two, practice areas. This approach allows you to provide a deeper and more compelling explanation of why they appeal to you, rather than giving a broad overview that might feel less specific to the firm. Focusing on 1-2 key practice areas also gave me the chance to use the word count more efficiently. I could then discuss other aspects of the firm that attracted me, including their client base, international or national presence, and the distinctiveness of the firm's training programme. I think this allowed for a more well-rounded answer.
When choosing which practice areas to highlight, I've also found it helpful to consider those that were more "core" to the firm’s London office (some lawyers at the firm might describe those practice areas as the "bread and butter" of the firm). This can help show your understanding of what really drives the firm's work. That said, if you’re genuinely interested in a more niche practice area, don’t hesitate to mention them. Just make sure you can clearly articulate why it interests you/motivates you.
Alternatively, as [USER=2672]@Jessica Booker[/USER] mentioned, there can be value in highlighting more than 1 practice area, or even noting the breadth of practice areas the firm excels in. Some applicants thus mention how the firm's rankings across various areas would provide them with a well-rounded training contract. As Jess mentioned too, many applicants end up specialising in areas they didn't initially find interesting and many big firms expect trainees to be open to a wide range of seats/practice areas.
I think [USER=36740]@Amma Usman[/USER] and [USER=36777]@Andrei Radu[/USER] would also have much more to add here. But these were just some initial thoughts!
Hope this helps!