I'm not readily familiar with an "AG1800" model. I think you mean the Panasonic AG-1980P (and the tunerless AG-5710 variant of the 1980).
The AG-1980P was equivalent to the NV-FS200.
There was no NTSC equivalent to the NV-HS1000, with is frequently reported as being slightly better than the FS200/AG1980 in image quality. Audio quality is still the same (which is excellent, better than the JVC line).
However, all Panasonics are still slightly inferior to JVC image quality, nuder typical conditions. There lots of if/or/but caveats here. So sometimes the Panasonic is better. It depends on the source. It's why most all professionals and serious hobbyists need both kind of decks, as they're different. Even within the same brand/manufacturer, the models lines vary -- as it does with the HS1000 and the FS200/1980.
The TBC integrates temporal NR. That's the main reason for debates concerning quality. The Panasonic tends to be more limited compared to the JVC, which is one reason the image quality between the brands differs. Same for Mitsubishi and some others that you rarely hear/read about.
More Panasonic S-VHS models?
The reason for the PAL 900s Panasonic model was likely no more than production runs. The AG-1980P had a long, long model lines, ranging from the early 1990s to around 2006. I forget the exact dates. In all honesty, the AG-1980P had so many variations that it should have been broken down into separate models (1985, 1990, etc).
The issue was never resolved. It's a worldwide epidemic that infests many devices -- not just VCRs. We just hear about them less, but it's very common. If anything, the older FS90 does not have the issue simply due to its age, as the problem is almost entirely from the 1995-2005 era. The issue was not publicly discovered until the mid 2000s, and by then it was too late. To this day, most manufacturers still deny the problem. Several lawsuits have ensued, and I'd not be surprised if some were still ongoing.
If any EU/PAL models were spared a capacitor issue, it's like happenstance, and was not intentional. For example, sourcing more-expensive parts from other EU or Asian countries, not the far East. I know that many JVC S-VHS VCRs were entirely built in Germany, and likely used local parts back then. It was just a different era for world commerce, and the infestation of dirt-cheap (unsafe! bad!) Chinese parts/products has not yet hit.