The bottleneck when synching up w/ Bitcoin Core is likely to be hard drive access and I/O time.
I have a 5 year old (full size) HP pavilion dv6 laptop running Windows 7... CPU usage rarely exceeds 20%, so changing the task priority does nothing to speed up the process.
With a 56 Mbps connection there can be many minutes when the network usage is only a percent or two, followed by periods where it's 10-50% or more; after sucking down the data it then has to crunch it all. So connection speed likely won't make a big difference.
Go into Task Manager (ctrl-alt-delete) and under the Performance tab there's a button for the Resource Monitor, which has a tab for the Disk; this will show processes with disk activity, and you can see there how bitcoin-qt.exe is keeping the disk activity pegged near the max (10 Mb/s for me) most of the time. Task Manager also has a Networking tab where you can follow what's happening there.
I still have 31 weeks to go and it's now taking ~1 hour per week of progress, or a little more. Back when I was still 1½-2 years behind it was 10-15 minutes per week of progress; at ~3-4 years behind I first began to notice it taking several minutes to click down another week.
Current total blockchain size is 86 Gb, and it's adding ~1 Gb per week of progress, so I'm guessing it'll total out at ~120 Gb.
This is definitely an issue for BitCoin if the thing pyramids in size to where nobody new can synch up with it.
I first started ~7 weeks ago and have been working on it ~3 hours a day maybe 3-5 days a week; with all the disk usage my machine is not very usable when it's doing this.
Hope this helps someone.