If you have a slow connection, make sure you use a download manager and it will go much smoother. There are free ones available, i.e., Free Download Manager. 

Each file has a 300 min limit when you start it.

I had a problem with this because my connection takes longer than 300 min for the 2.1gig files.

I wrote customer service and Lars was very helpful and sent me links with no time limit and I got all my files.

Cool, cause my files are still downloading from when I started this post.  I cant believe it.   Thank you very much.  Ill  try that.   As long as we can redownload at anytime after purchase its cool.  Im going to work and download and put on disk to transfer here.  P.S.  Talked to Lars and he is sending me links closer to my location.  thanks again.   REally appreciate all of your help.

Hi everyone, i also bought the sonarx1 upgrade and my files are taking forever to download as well. Problem is that im using the libraries wifi and i dont have the time to wait 5hr37mins! So who is this LARs and could he help me speed up the process?

Hi, Do I have to reinstall ver 8 to upgrade or can I clean install the new version being prompted for evidence of ver 8 ownership like insert original disk or serial number.  I dont have the old ver installed anymore since system crashed, have the box, disks, contents right here though.   Just kind of crazy a piece of expensive software requires you to keep old files on your drive and worste entries in registry.   Thanks much.

Shreddi
Just kind of crazy a piece of expensive software requires you to keep old files on your drive and worste entries in registry.  

Unlike some other companies, Cakewalk doesn't play that game. The upgrade affects Pricing Only. The only connection is your registration for the previous version, and Cakewalk has that on file.
The different versions are separate entities. Your upgrade is a full install, and it can coexist on the same computer, or be installed on a completely different machine.

Thank you very much Robert.  but I tried to install the upgrade on a new machine.  Old one crashed and never reinstalled ver 8 producer.    I get an invalid serial number error so was wondering if it is actually looking for a pre-installed version or searching registry for ver 8 serial number?  If I can install clean then....   hmmm   I got the serial numbers on my account page,  maybe copy paste doesnt work for it, no screen scrape, which could be.  If I have to reinstall ver 8 so it recognizes the thing I can do that,  I hope it writes over same directory cause I dont have a ton of space on the drive.   Thank you very much again.  Ill  try typing serial numbers in this time.

No, you don't need to re-install S8.
If I remember right, Copy/Paste doesn't work because it doesn't populate the fields correctly.
Also, make sure you are entering the serial number and registration code in the proper boxes.
They are not the same thing, and it's easy to mix them up.

Watch O's and 0's.
If you, in fact, have an invalid serial number, you may need to call Cakewalk.

FDM/free download manager.. you can leave running, and it'll even switch off the pc when it's done if you tell it to..  and it'll support resume, so even if it flakes out you can restart/continue with it :)