Movement technology and long term rate stability

By way of preamble, the technology that has been incorporated into movements in the last two decades or so is exceptional. Omega has coaxial with a silicon balance spring and alloys for megnetism, Rolex has particular technologies, Seiko (Grand Seiko) has a new escapement and JLC has made improvements to reduce stress on the movement and increase power reserve. It is clear that stability of rate and positional variation have reduced dramatically by just reading the threads here. I had an omega 9300 that was about 3 seconds a day regardless of power reserve, position (whether I wore it or not). I also have a JLC Master Geographic from the 1990s that I have never serviced (I don't know the history) and it is also about 2 to 3 seconds a day although there appears to be more isochronism. I guess that one could argue that a range of different factors went into those differences, apart from technology, there is design and finish, to name some.

Manufacturers provide a performance number and guarantee for number of years. I actually don't know the guarantee period and whether the manufacturers guarantee stability of rate during that period of time. If we assume that they do do that - would that provide some evidence of how they expect the timepiece to perform. However, if we leave that aside, without looking at stability of rate over time and by position, how can someone evaluate how different technologies incorporated within a movement impact long term performance?

This is my long winded way of asking should I sell everything and purchase the new JLC master control, the new Grand Seiko or an Omega Railmaster?

@Archer - that is a good point. I think long term is anywhere over around 5 years. I can see why JLC stuck to reducing the amount of stress on the movement rather than creating a new escapement.

My opinion (like buttholes, everyone has one), is that any "accuracy" in a mechanical watch is a combination of two things: how well was it manufactured, and how skilled is the lady who adjusted and regulated it?

Using my local watchmaker as an example, he warns me when a watch isn't going to keep time how I would perfer, because it wasn't made to.

One of my watches is a 1914 Ingersoll wrist watch, and rate in positions is horrible. But I have it set to where it'll keep time 15 seconds a day or better on my wrist, and that ain't bad.

I've had watches that weren't chronometers still keep time within whichever spec you like. Another watchmaker I know adjusted and regulated a Vostok Amphibian to within 4 seconds day or better in all positions.

Now to get into the long term. One of my personal motivators for getting a watch serviced, it doesn't keep time like it did previously. Whether that takes a year or a decade, since I rotate the watches, isn't significant. But a watch that was a consistent +2 is now a consisten -3, means service to me. And when the watchmaker is done, that same watch might be +3 instead.

Lots of factors to consider.

Dammit. I just paid a premium for a Martin Braun Selene because the moonphase is accurate for 122 years! (OK, I didn't buy one, but I always liked that model, especially with the big Gibeon meteorite dial)