CraigAB's response is right on the money. Inspiration, the only way to really understand how reeds work is to try them. You cannot go by comparison charts or reviews - what is bright for one person is dark for another.
The point Craig made about adjusting reeds is important; reeds are not precision items, and must be adjusted to suit the individual player's needs. There is no difference in the manufacturing process for reeds of different strength; once the reeds are made, they are graded for strength and then marked.
Also, reeds are made of cane, which is an organic material, and has wide variations in density and flexibility. Which is why Craig said he has never found a balanced reed. (Neither have I...)
You just have to accept the fact that you must buy many reeds. If you learn to adjust them you can get most of them to play well (the ATG system is very good for this, as Craig mentioned - but it is expensive). You should always have about 4 reeds that play well, and rotate among them day by day. That is, play one reed one day, one the next, and so on. As your reeds begin to wear out, add new ones to the rotation.
It's good to experiment with different kinds of reeds, but you should try several of each kind before making a judgement.
Good luck - reeds can be the bane of a woodwind player's life, but with a little thought and practice, you can minimize frustration.