Chrina and Exal XR2 are comparatively cheap rims so do not have the cosmetic finish of Open Pro or ST17.
This is quite true. Open Pro are welded at the seams, wereas Chrinas are pinned.
Can we just discuss what a "strong durable fast" rim is?
1) Strong - should survive pothole hits, carrying 20 stone rider, panniers full etc
2) Durable - braking surfaces do not wear
3) Fast - light wheel that will accelerate well. I am ignoring aerodynamics
Open Pro are stronger and faster than Chrinas but not as durable.
If you add the 4th factor to the list, price, you will realise that no one rim can do it all. In fact if a rim came along claiming to be all those things and cheap then I would not believe it. Chrinas are half the price of Open Pros
In your deliberations you have also ignored spokes. Double or triple butted spokes will be slightly lighter and (debatably) give a better ride and be stronger