I did exactly what Bats mentioned in his opening post , except I did it in 2006 and ran SONAR 6 PE under XP until 3 1/2 years ago . I was happy through out that whole time .When I finally got a Win 8 computer and went w X3 PE I found myself in a whole world of SONAR learning curve hurt ....looking back on that phase , I think one of the things that got me through that whole experience was people here on the forum helped me learn the software ...
Then when I got SPlat I had gotten a little more used to the learning curve ...Admittedly I did not like all of the updates because it screwed around way to much with my workflow ....
I went out and bought 6 other competing DAW's that are every bit as good as SONAR because I didn't like the idea that some of the developers at Cakewalk were designing things in a DAW that I didn't feel was relevant to my particular workflow ..
When I play my guitar it's a right handed guitar , when I'm done playing it , I put it in the case , When I go to play it again I do not appreciate that someone decided to change it over to a Lefty
that's what some of the SONAR updates did to my work flow ...
As far as the OP's original question / statement ...if it was me I would put 6 PE on my brand new computer only because it 64 bit and it is a know workflow ...Then I would take it from there ....
if you could score SONAR SPlat you would probably be in the same boat as every other one of us ...it is pretty awesome and it will probably run for years ..the main disadvantage I can see is you have had plenty of time to have made the switch from SONAR 6 to SPlat or what ever ..your reasons for doing so are probably personal and make perfect sense to you , so I will accept that for what it is
IMHO the biggest disadvantage to upgrading SONAR in your case may be that there may no longer be the type of help SONAR users have gotten for years on this forum ...once the forum goes bye bye all that collective user knowledge that we have had for years may only turn out to be Dust in The Wind
Kenny