buy a evo ssd, it will sync the whole blockchain in 1 hour(tried it myself), and it's not expensive at all
For most of us the bottleneck is probably still the internet connection. Even slow mechanical disks can write >30MB/s on average[1], even a 100MBit/s connection will not deliver 30MB per second. In order to to sync within 1 hour you would indeed need a 100MBit/s connection and the disk should not have a big impact, since you would receive data at ~9MB/s, unless you use the disk for something heavy at the same time.
[1] http://www.tomshardware.com/charts/3.5-hard-drive-charts-2008/Average-WriteTransfer-Performance,659.html
well that's wierd because with my 850 pro i've synched the whole chain in 45 min, and i don't have 100mb, but only 8
At 8Mbit/s you would at max get 1 MB per second. In 45 minutes thats 45*60s*1MB/s = 45*60*1MB = 2700 MB. Maybe you just rescanned the blockchain or had an old existing bootstrap.dat still in the directory, but the numbers dont add up.
Headers first synchronization now allows faster synchronization with parallel downloads of peers which allows faster download of Blockchain simultaneously. Torrent is basically the same speed or even slower since they need to do verification of the blockchain before downloading more. 0.10 is not backward compatible but I would assume its okay to download from torrent. Correct me if I'm wrong.
Using the torrent is fine, its probably slowing down the sync though. As you said you cant download and verify at the same time with the torrent, but you can when syncing with 0.10. directly. There might be some cases where you have problems finding enough good nodes though. If you allow no connections from the outside you are limited to 8 connections. If those 8 peers are connected with a cheap DSL home line with e.g. 2MBit/s upstream you will probably be better off with the torrent.