orm - Which metadata definition format to use with doctrine 2 and symfony 2 -

i'm starting use symfony 2 after time using symfony 1.4. know metadata format easiest , fastest learn , use.

i know people clean hands when comes better other thing, specially when things supposed equivalent. nevertheless, i'm asking make recommendation considering folowing:

1. i have experience symfony 1.4, using yaml format
2. the amount of documentation each format.
3. any other thing may consider i'm not xd

i use yaml configuration files, ... doctrine metadatas. use xml because refer xsd know kind of node can use...

for once, xml looks more readable cause each field takes 1 line defined. generally, yaml makes break line each field-node's attribute.

edit: after 2 years practicing symfony2, use annotations everywhere doctrine metadata, validation rules. use yaml translations.