Not sure if your PM box is full but here is the answer to your questions: Both are very capable subs. Mags are NOT 2x as good as RL-ps. A sub is only good if it is the right one for your application. For example, an IDQ is a very good sub, but not good for a buyer that wants to run 3000 watts, and visa versa an Orion H2 is a good sub but not good for the buyer if they only have 200 watts, etc... Anyway, from my knowledge there has yet to be a disappointed customer for either the RL-p or the MAG. Both have great sound quality if put in the right box and so on. For your other questions, if all things being equal (power and such) two RL-p 15's are probably going to be louder over one MAG due to double the cone advantage. And there is no such thing as better SQL, in the correct install both can get loud and sound very good doing it. I have tested both subs and I like both of them, but each has their advantages and disadvantages. There is a very high possibility that (once again if installed properly) you are not going to hear all that much of a difference in SQ. You need to figure out if you want more output now or later? There is that MAG SA deal I believe.