Advice Selective Travel Insurance for Cotswolds Trip?

[Interstellar Balloon Z]

I'm in the midst of planning a three-week vacation in the Cotswolds for June 2025, and I've been hearing a lot about selective travel insurance. Has anyone had experience with this type of insurance? Is it really beneficial for a long trip like mine, or is a more general coverage better? What specific things should I look out for when choosing insurance for my travels? Would love to hear your insights!