I've heard that the drives are slow.
This depends on what you're measuring, and who it is saying that they're slow. Their random access times aren't anything to get excited about, in sequential read they can sustain 100MB/sec quite easily. So I wouldn't install a performance-critical database on one, but for streaming video they're fine.
Even torrenty/download stuff - unless you have gigabit broadband you're going to have other bottlenecks, don't forget that the OS will do a lot of write caching for you.