Evaluating Classical Music Albums

How do you evaluate classical music albums? 
First, what do you look for when you’re deciding which album to stream or buy? Is the conductor/orchestra more important, or is the record label? How important is the date of the recording?
Second, what do you listen for in an album that you already have to determine the quality of the recording? This can obviously be divided further into the musical quality and the sonic quality of the recording. What factors are important in evaluating these qualities?

Thanks for the advice.