Moving from imovie 06HD to mor erecent version

I have stuck with imovie 06HD as I like the layout with the normal timeline and early reviews of imovie08 indicated that importing interlaced PAL video the quality was reduced by about 20%.

I am keen to try a more recent version of imovie as a stepping stone to imovieproX and to avoid the annoying glitches in imovie06HD. Can the forum assure me that there is no loss of quality now when importing interlaced video into later versions of imoive?