It has actually been quite some number of years since Arnold & Son has been taken over by La Joux Perret and has started their present renaissance.
Since that time all their movements are in house and all their watches have in-house movements.
The present director of Arnold is one of the most passionate watch collectors I have ever met and you can see that passion in the collection.
Although everyone knows that the present Arnold has absolutely nothing to do with their English predecessors other than the name, they act like they do have a connection.
The ideas behind the watches are historical, but declined in modern watchmaking.
I have heard the criticism that much of what they are doing has been seen before, but that is what happens when one uses more than 100 year old developments as ones models.
(I have heard this particularly with respect to the star wheel model, but no, this is not an AP development, AP saw it in older historical English watches too

)
Disregarding the model politics, Arnold is also has another connection with the original John Arnold. At the time Arnold was the biggest supplier of chronometers to the royal navy. This was because he had developed a chronometer that was simple and reliable, thus simple and relatively inexpensive to make without extensive tweeking. He was able to make and sell for a good price larger quantities of his chronometers than the competition. Todays Arnold and Son are also investing heavily in design for production so that, for example, their tourbillons are relatively simple to make and repair, not needing the intensly trained specialists of other brands for assembly and repair. This is good news for all customers thinking about the long life and happyness of their watches.
I would say that Arnold & Son is worth a closer look.
Don