The AM is not a machine gun to a knife fight. it depends entirely how you ride.
You’re in Scotland TLR, AM too much for Golspie or Laggan Black at speed with those jumps and terrain!!
However based on your description I would wager an AC would be a slightly more appropriate bike either 26″, 650b or 29er.
In fact for what you describe with the touring bit I would probably recommend the 29er as it is long legged as well as capable.
You’re welcome to have a thrash on mine if you want. Dipper of Gravity sports also has a Demo, which is one of the best ways to know.
I came from an AM, which I loved for all sorts of stuff and you wont be dissapointed if you go that route, but I wanted something that was a bit lighter and pedalled better for longer events/trips. The pedalling better is mainly due to weight and wheel size rather than any difference in suspension of which there is little.
On the Ion replacement, the Helius range is and will remain a little more plush/sensitive than the Ion due to the linkage design. There is nothing much in the Ion in terms of features, other than geometry change in the rear linkage, that isn’t in the Helius range.The Ion is intended to be harder hitting, but they have got the weight down to the same as the AM. The AC is still lighter.
You can always get similar angles cheaper with mass produced frames, you can’t spec your own if you know what you want and the build quality and attention to detail is second to none. They will last a long time under all sorts of use.
I suggest you get in touch with Richard at Gravity Sports as I think he will be able to hook you up one way or another with a demo on most of the models you are interested in through a Network of dedicated and generous Nicolai enthusiasts and his customer service is superb.
Also, Nicolai are not that expensive, against Carbon from other quality brands they are usually cheaper and Santa Cruz make them look like a total bargain!!