What are some alternatives?
When comparing aDownloader and µTorrent, you can also consider the following products
qBittorrent - Lightweight and open source torrent client that runs on all major platforms.
Deluge - Deluge is a full-featured BitTorrent client for Linux, Unix and Windows.
Transmission - Transmission has the features you expect in a BitTorrent client: encryption, a web-based interface...
FrostWire - Easy to use BitTorrent Client and YouTube Downloader in one, with built-in search and music library.
BitTorrent - BitTorrent is a peer-to-peer program developed by Bram Cohen and BitTorrent, Inc.
uTorrent - uTorrent is a light customer from BitTorrent that utilizations less assets than others of its sort.