I live in the UK and spend most my time in the northern 'mountainous' areas of England but I'm starting to get more involved with higher climbs so I need to think about getting new kit. However, I'm not really sure what type of boots to get. I see people taking about Nepal EVO GTX and then plastic boots like Scarpa Maestrale and also boots like the Koflach. From what I've read people seem to prefer the plastic boots at the higher altitudes where it gets cold but I'm not sure why. What are the advantages of each type of boots and what kind of activity suits it best. I'm mainly planning on spending most my time in the Alps, Andes and Himalayas.
Sorry if this is a stupid question but I've spend a while look around the net and I'm still not entirely sure.