I have both (not in the same house lol) and kitchenaid - make sure they're dishwasher safe the mixer bits. Some cheaper options if I recall said wash by hand - hah.
I find kenwood much more sturdy but have a chef type (can't remember which) and its super bulky on the kitchen counter.
In my smaller kitchen I have a kitchenaid and it's nice.
I honestly cannot say I have a preference. If I had to choose one, I don't think I'd mind whichever. The pasta shape maker in kenwood is worse than kitchenaid. The kenwoods food slicer weakened quite quickly but it went through a lot of use. Kitchenaid accessories are okay so far but they don't get as much use as the kenwood.
To be honest op, you'd be happy with either. Like someone above said though, kitchenaid is quite easy to tighten up and instructions say something along those lines if I recall correctly. Grab a pdf online and have a quick read, I think you can align.
My kenwood gives some odd bangs and I'm unsure what to do, probably would just replace with a newer chef model or something that matches the current attachments.
I think I prefer kenwoods more sturdy feel OH and having both I 10000000% prefer the way kenwood lifts and is sturdy, I find kitchenaids head is so heavy haha like lifting it and dropping isn't as smooth is kenwood. That annoys me but its something I live with.
Depends what you plan to make etc. And which attachments are better. Although I think kitchenaid attachments universal and kenwod you have to make sure it fits into your specific kenwood and I recall searching under it (or maybe that was coffee machine) for its specific make/code.
And don't quote me but delonghi and kenwood same family? I remember calling for repairs for coffee machine and it was mad expensive and it got me thinking how much they'd want to fix the banging in the kenwood and thought I'm probably better off replacing it eventually. Still mixes well.