There are no CRT monitors made in the last 10 or 15 years that are 480p. Are you talking about TV quality maybe? An old TV that you send a higher resolutoin signal will be blurry and shaky but not a computer monitor that is even close to modern. Even a cheap 15" CRT should be 800x600 resolution which is a lot higher than 480p.
CTR monitors look crisper at all resoltions than any LCD, LCD monitors/TVs really only good good at he native resolution, a CRT scales well at any resolution.