I'll tell you something about the slugishness Mike.. now I've thought about it. When FS9 came out.. we had a number of models either in the workshop or recently released. The Tridents spring to mind though the same applies to all of them. DM went on holiday just before the new Trident2 (FS2002 model) was due out. It was 'there' all but for minor detail. I spent a week fine tuning the fuelburn for maximum range covering some 30,000miles in the air running simultaneous flights on 2 pc's with different settings. I got it where it needed to be.. DM came back off his hols and it was released. 2 weeks later, FS9 hit the streets and suddenly, the T2 ran out of fuel before reaching Cyprus!!
All our models suffered the same fate showing that subtle changes in drag between FS8 and 9 meant performance was different 
I have dragged the Viking into FSX.. it was one of if not the first model to dip it's nose into the new sim but haven't spent much time with it there. It looks very much like drag characteristics have changed again between FS9 and FSX as they did between 8 and 9 giving the older models back the performance hit they took earlier. Many of the models have since been re-released and updated.. ALL of DM's fleet.. to full FS9 standard and compiled using FSDS3. These port over to FSX much better though still suffer a little. The V trio remain exactly as they came out of the box and were never updated outside having both FS8 and FS9 cfg's included in the package
So there you go.. 10mins of Sunday morning gone and already I've bored you to tears. At least (if you're in the UK) it will have taken your mind off the horrible weather outside
Hope you're all fairing better elsewhere 
ATB
DaveB
Now I know that could be the reason (not had chance to do the test flight yet) Didn't realise either that there would be such a difference in AC designed for different FS versions. Glad you "Dragged" the Viking in to FSX Dave 
As for the weather...sorry not good there, Queens Jubilee too.. 
Warmish Winters day here...'til the Sun drops and then it's cold