I live near Keswick with 2 young kids. Been here 10 years and wouldn’t like to leave. Love it, but then it suits my lifestyle.
Pros: Good schools, great countryside, friendly people, easy access to M6/mainline train etc. I work locally so no worries with long commutes. Brilliant road/mtb riding, climbing, fell running etc.
Cons: It does rain more than most parts of the country, property is expensive, town centres are rammed on sunny weekends (although easily avoidable). Kids are likely to need a lot of transporting in their teenage years as public transport links aren’t great and their friends may be in a 10 mile radius. Difficult job market if you’re not into minimum wage tourism/catering jobs, many commute to west cumbria (sellafield), penrith and carlisle. Low on culture- theatre/live bands/eating out etc that you may be used to in a big city.