Thanks for your comments.
My first video editing package was Pinnacle Studio 9 (then 11). I used to cut each panorama into 1920 x 1080 stills and then do a slide left transition to slowly slide out the first still and slide in the next.
When I moved to PD8 I was delighted by the improvement (both in quality of resulting video and features), and the Magic Motion effects saved so much time, especially when panning across and zooming into panoramas.
Sadly, it appears like most "modern" software the rush for more features has had an impact on performance and, in this case, quality. The comparison can be seen on Youtube: http://youtu.be/ZIc9tATK2Es.
The first 40 seconds was produced in PD10, the second 40s is actually PD10's re-rendered PD8 effort (hence twice rendered and slightly lower quality than PD8 manages on its own).
My "upgrade" to PD10 was mainly on the "Blazingly fast".... "Fastest in the market" adverts but sadly this appears to be sales hype rather than reality. Windows live movie maker now seems faster, and Adobe Premiere Elements 10 on a par for speed.
So for the present I'll stick with PD8.
Ta!