I have a Kitchen Aid.
Love it.
However it's really a brand/aesthetic choice.
I think the KA has more attachments - but as a stand mixer in its own right I honestly don't think it's better then the Kenwood my DM has.
So it might be worth thinking about how you plan to use it and which attachments you might want in the future and considering you could buy the Kenwood and some attachments for the same price as the KA?
Other than that it is simply a case of can you/ want to justify the extra cost on the KA?