I'd consider it a better idea, yes. Transmission is good, mimimalist BT client though. I mean, you could download stuff onto your N900 if you absolutely had to and then transfer it to your PC. I would only suggest using BT over wifi - doing it over cell data, even 3G, may go over your rate limit (even for "unlimited" ) plans.

What I'd look into doing is finding a client that has a webUI that you could connect to back on your home PCs (I think uTorrent can do this but its closed source and I don't trust non-FOSS programs for torrents due to the sensitive nature of the protocol and what is sometimes transferred over it. Try Vuze?) and you can control it from your N900 instead. Much less resource heavy.