Obviously, you need to do what's right for you, but we have seen a few people on the forum leaving without citizenship without ever intending to live in the UK again, and then regretting it a few years later when they've decided to move back to the UK and have to start from scratch with visas again.
In some cases, they either can't afford or can't qualify for a visa to come back, it now takes 5 years and £5,000+ in visa fees to get back to ILR, not to mention the £18,600 minimum income requirement for the UK citizen (or £62,500 in savings).
If you have ILR now, then you can leave the UK and move back within 2 years without losing the ILR, but any longer than that and you have to start over.
Ach, I think I quoted the wrong section, but I'd fully second this.
If I were eligible for citizenship, I'd do anything to obtain it immediately. I'm less than 18 months away as the rules currently stand. It's just such an expensive process and so time consuming. I just don't ever want to go through any of this again.
After weeks of sitting on my original post, I think we're definitely still leaving, but we're giving it at least 6 months to wait and see. But I just cannot see leaving without citizenship. And then the plan is for my husband to get US citizenship.
It's an upsetting time. Both places are frankly undesirable to us at the moment.