I've owned a fair amount of Yamatos over the years, probably close to 100 in all scales, although I've sold a lot, so my currrent total is about 50.
Given the complexity of the designs and the number of parts involved, I'd say that overall the durability, fit and finish of Yamato toys is pretty good.
I currently have about 22 x 1/48 VF-1 (I used to have close to 30) and the only problem I've had is a single BP8 breakage on my very first VF-1A Hijkaru, which was 100% my fault.
I've owned many 1/60 VF-1 although only have a few remaining, but never had a breakage on any of them.
I've had 6 or 7 VF-11B FAST Pack, and never had a problem. I used to have a dozen non-FP VF-11B and only had 2 hip breakages.
Probably owned about 15 x 1/72 YF-19/VF-19A and only had one Tab-B and 1 hip breakage.
The new 1/60 YF-19 seems pretty sturdy so far.
The VF-0 is apart fom the shoulders, which is either a material flaw or a design flaw (TBC) a pretty sturdy toy overall.
My 3 x Q-Rau are all fine.
My 2 x Konig Monster are both fine except some stress marks in one of them.
My 1/72 YF-21 are all fine. I have 5 remaining.
It's a given that the more articulation, small parts and features you put on a toy, the more fragile and less durable it's going to be.
The only Yamato product that has really disappointed me was the Garland. I had no problems with the shoulders, but the metal bars connecting the front wheels snapped on both of mine.
Graham