>In-place upgrading is better than it used to be e.g. http://blogs.technet.com/b/chrisavis/archive/2013/10/01/performing-an-in-place-upgrade-of-server-2008-r2-to-server-2012-r2.aspx
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>One might argue it depends on the complexity of the current server. But that's a two-edged sword:
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>- The more complex the current setup, the greater the chance something will go wrong in the upgrade, and it might be a PITA to troubleshoot
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>- But, the more complex the current setup, the greater the chance you'll miss something setting up a new, clean install. And it might take a long time to get everything set up like the old system

In the particular situation, for a specific upgrade, it is ok to restart from fresh because this is something that is not widely used yet and no particular settings apply on that one.

>An in-place upgrade may not be possible if there are any incompatibilities. For example, SQL Server 2005 is not compatible with Server 2012 or 2012 R2: https://support.microsoft.com/en-us/kb/2681562

Ok

>In a perfect world you would have complete instructions on how to set up your desired environment on a new server, so it would not be too onerous to do a fresh installation. But, an hour for an in-place upgrade is hard to argue with.
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>If you could spare an hour you could test the in-place upgrade first. If that doesn't work, blow it away and do an install from fresh.

Thanks