I guess it depends on what you're after - if you're just wanting a mixer for cakes and such then the Sunbeam would probably do the job well enough, but then so did my mum's nearly 30 year old Kenwood. If you want it to do more than that and aren't planning on shelling out for a Thermomix any time soon I'd go with the KA.
I find the dough hook on my KA works really well not only for breads and pizza dough, but pasta as well. Beating eggs for desserts takes 1-2 minutes tops and whipping a litre of cream about the same, plus it's quieter than any other machine I've played with. It comes with the whisk, flat beater and dough hook as standard.
The attachments are what really make the KA though - I have the rotor shredder/slicer, so much easier than a food processor as it shreds directly into whatever container you want, even the saucepan you're about to cook with. I've also just gotten the mincer/grinder and sausage stuffer attachments for Christmas so am starting to play around with making my own sausages. Next up is the icecream bowl
Plus it just looks sexy on the benchtop.