The differences between it and the W800 are roughly:
- 480MB of internal memory
- Screen quality and resolution are massivley superior
- 3G (if that floats yor boat)
- and a certain amount of exclusivity - every man and his dog has a K750 or w800 - fewer of these around.
I will say white makes it look even bigger than it actually is tho, but everywhere i've taken it out i've had interested queries as to what it is/does.
Photo quality is superb as well in all light conditions. Phone can be used almost exclusively closed - only when you need to input a number/text or turn it on does it need opening, but personally i never turn mine off.
Also makes a funky "swish" sound when it opens...