Hey I have both W55 & W80.
Both are 7.2 Mega pixel camera. Both produce superb Image quality.
In good light condition both produce almost similar image. But when it comes to low-light or difficult light condition W80 is best.
Here are some benifits of W80 over W35/55/70.
> W80 has BIONZE Processor produce more Vivid and acurate colors. D-range optimiser function works well.
> W80 is really FAST. It is its best advantage. W80 can fetch photoes at 2.7fps. W80 with Flash beat other cameras without Flash.
> I like W80's menu style which is similar to PSP.
> W80 has optical Image stabilizer. It has sony's famous technology Double-antiblur solution. So reduce the chance to have blurry photoes.
> W80 has 35mm (f: 35-105) lens while W35/55/70 has 38 mm (f: 38-114) lens. So W80 can take much wider photo than W35/55/70.
> There is no facility of additional lens accessories for W80.
> W80 has Full HD-Output (Still image only). So you can enjoy HD images on your HDTV. HD Cable is optional not supplied.
> W80 is full of features like Face detection technology, 9-point area measurement and many more.
There is only one difference between W35 & W55 ---> W35 has 2 inch LCD while W-55 has 2.5 inch LCD.