Well, the sale ended yesterday, but you could have bought it at discount even without downloading, since purchases can be made both from within Flight sim, but also from the Web store, where you don't need to install the Trial first.
I've tried a random Cloud9 download (EHAM) and it works just fine.
Could you please say exactly which file was so slow ? Because, each file use a different server so, it might be one of them had issues. However, it's usually very uncommon, since we don't host downloads ourselves (we'll never be able to provide enough bandwidth for everyone), but we use an high-volume bandwidth provider (Mediafire), which is specialized for hosting large downloads using several hundreds of redundant servers so, download speed shouldn't normally be an issue, but one of the servers might have been particulary taxed, but it's usually fixed in a couple of hours or so.