I have a 7mb adsl.
It took me 3 days with a 100MBit connection with bitcoin-core. As has been said: you sync only with one client, if you are lucky they have a fast connection. With the torrent you will use your line at ~90% (keep 10% for orga/surfing) or even fully*. It went up to When you are done keep seeding to help others.
* Edit: just did a test. The torrent runs at ~ 24MBit/s after ~30 seconds. bitcoin-core is never going to achieve that rate.
I'm in Australia on ADSL2+ (24Mbps max is quoted by companies so I'd think ~10Mbps is true speed as max torrent DL speed I get is ~1150kbps ~= 10/8).
I am getting 450kBps rate presently, which I'd have to think is ~50x faster than Bitcoin Core.
There must be a better way than having 1 peer sending the blockchain; the upload bandwidth jammed to a halt for 4-5 days is infeasible at the painful induction crapshoot.
Best way to resolve the issue? If you've either 1) DLd the torrent once before or 2) waited while BTC Core did its thing for 4-5 days, or 3) like Bitcoin ... seed the torrent!