Funny, I prefer cedar for Baroque music
Wel, I've been hunting a new spruce top guitar for a about a year and tried many, many, many, too many actually. One thing I find useful though is to be able to try it with someone else so you get to listen to the guitar and you have someone who can listen and spot weaknesses of the instrument you may not be able to hear by yourself.
Having the possibility to compare guitar is also a plus.
The acoustic of the room also has to match extreme conditions or conditions that for you matter the most. e.g., if you want to play in public then large room with echo is good. If you want to play for yourself only, match your practice room as much as you can.
Consider the age of the guitar as well. A brand new spruce will evolve over time and may be a bit disappointing compared to a brand new cedar top. But if you have the opportunity to try more than one guitar from the same builder, you will get an idea of how it ages.
Falling in love is probably the number one criteria though... follow your heart!