One overall question: These ratings are so high. Is this a tribute to Pentax lenses or does this magazine tend to always rate at the top end of the scale? Perhaps some comparison ratings from Canikon would help. or better yet, from Zeiss and Leica.
Originally Posted by thibs 
DA17-70 SDM
*Vignetting visible at 17mm and 70mm where you need to close aperture two notches to eliminate it.
*First half of zooming range gets chromatic aberation of red/blue fringes, very visible. It is THE drawback of that lens. Not better than 16-45 it seems on that point.
*Distortion: very noticeable until 21 where it becomes less intrusive and is pretty workable.
*Sharpness: performance level exceptional until 50mm where it goes down, especially wide open.
Seems the DA16-45 is much the better lens then. I'm not surprised, since it seems to perform way beyond its intended scope.
Originally Posted by thibs FA77
Slight vignetting, very slight chromatic aberration, no distorsion. Very sharp from wide open but not homogenious (center a lot better than corners), homogenious from f/4 and up.
Again, if you don't need the light, the DA70 is better deal.
But light trumps all, so it would not be right to rate this less than the 70mm. Also, the lack of sharpness at borders wide open is a feature, not a bug. That's what makes it so good for its intended purpose, portraits.