PD8: Upgrade or clean Install?

Greetings,

i would like to know which way is "better".

Should i just upgrade PD7 to PD8, by simply "installing" PD8 over PD7.

or

Would it be better, to first uninstall PD7, then do an install of PD8.



My Windows 7 64Bit is actually a bootcamp installation, so not much really of a hassle on doing uninstall of PD7 then install of PD8 . . .

I am asking, because i read somewhere, that someone did the first step and saw a big performance drop!
But then, uninstalling everything and then installing PD8 "clean", the performance was back to what is was with PD7 or even better . . .


What do you guys suggest?

TY,
FM.

 

I think, i ll just uninstall it . . .