Types of Braces. Metal "speed" braces are a brand of "self ligating" braces. Clear ceramic/crystalline braces are more esthetic. It is most important to select the orthodontic specialist that you believe will treat you best as opposed to picking the type of braces. Normally, metal vs clear brackets work similarly.
Metal. Treatment with metal braces is the most efficient. Minor slowing of treatment .
Depends on need. If you're interested in cosmetics during treatment, go with ceramics. A doctor must take into account the needs and desires of the patient. Both techniques can work well and selection of appliances can often be a patient's choice.
Depends. On what you mean by better. Are ceramics more effective-- no. Faster-- no. A more pleasing way to straighten teeth for some people, especially adults who do not want to be seen with metal in their mouths?-- yes. Talk to your orthodontist about the pros and cons of each and chose what is best for you.