I use soulseek for windows quite often, and I find the Browse User feature very helpful to discover new interests from people that share the files I'm searching for (and therefore usually like). I'd personally like to see that feature implemented when "right-clicking" on a file (or selecting a file and then selecting a "browse user" button).
I agree that there are better options for chat rooms around. I'm divided about private messages, they've been useful sometimes to contact the person sharing or requesting a file (they sometimes ban you if you don't share files too); if it's too much, it's sacrificable though.
Thanks for the rest! I hope to use it on my soon to be N900 :-)

PS. I've never used Nicotine, but Soulseek if very resource friendly afaik; much more than other p2p applications, probably because it doesn't support multi-source downloads.