As others have said, £25,000 isn't really high income, but there are other things to consider. First, having children, you'll be eligible for Child Benefit. This is £18.10 for the first child and £12.10 for any other. It's paid every 4 weeks, so for you, that would be £120.80 each time - tax free. Also, medical care in the UK is free! True, you pay for it in taxes, but the tax you'd pay for the NHS (National Health System) is far less than an American HMO Family Policy is per month. And you don't have to worry about co-pays and deductibles each time you see a doctor. There is a small charge for prescription medication. It's £7.10 for each 4 week supply in England where I live, but Scotland has just dropped their price to £5.00, and will make them entirely free by 2011. There are also other monitary benefits that you can get, such as Child Tax Credit and Working Tax Credit. These depend on your income during the previous year, but when I first came over, I applied using my previous year's American income and I was approved. Remember, one dollar is only worth half a pound, so if you've been living on next to nothing, there's a good chance that you'll qualify. Some things here are more expensive, such as gasoline at £1.11 per liter (over $8.00 per gallon), and utility bills are set to rise 30% this winter, but if you start getting into trouble, the government here is very generous in the help they give. Your local council will pay all or part of your home payments as well as your council tax if your income falls too low. And you can be approved with as much as £6,000 still in your savings account. I fractured my wrist last year and they paid my entire rent and council tax for 2 months. I even got additional tax credits to help me through. In conclusion, since you said the main draw for us is the experience of living in Scotland, I'd say go for it! My family is poor, but we love the chance to experience foreign cultures. We're struggling to save up now to move to the continent - just because we feel like it!
Good luck