Doing the first time maintenance on my GF's 520 reminds me starkly why I build my own wheels.
The component set in the wheels is ok, even though M475 hubs have next to nonexistent seals (pushing the hubs chuck full of grease should help with that though). Rims are 36H Bontrager TLR and seem sturdy enough. Spokes are non butted stainless which is not optimal for any use but they'll do. I have DT Swiss Alpine III's as spares for the both of us so if a spoke breaks the wheelset is only going to get better.

But the tensioning on the wheels was a joke. I considered a full detension and retension cycle for both wheels but luckily I was able to get the wheels to an ok tension and straight without too much of a hassle (a tensionmeter is a lifesaver in these things). I measured a 60kgf difference between the most tensioned and least tensioned spoke on one side(!!!). That's ridiculous! Good thing none of the spokes were actually slack or I may have had to replace those already as we've done some rought roads for testing purposes.

What kind of experiences have you had with factory built wheels? I'm starting to think they are merely assembled when the bike is delivered and a pro needs to go through the wheelset before it's actually usable.
Sad thing qualified wheelbuilders seem to be relatively rare...