Everyone has a personal preference, so you're going to have many different options thrown at you. Truth be told, there are hundreds of great subwoofers on the market, and many of them are very similar. It all depends on what you want. First you wanted SQ, now you're talking about SPL. Certain woofers are designed for certain things, and no particular woofer can be perfect in every aspect.
The RE SE's are very, very nice entry level sq oriented subs that can handle decent power and get reasonably loud. They aren't the best, but they are far from the worst. For what they cost, they're excellent. Buy them, build a nice enclosure, power them cleanly and enjoy the results.
You're not going to learn everything by asking questions on forums and watching youtube videos, because no two people think exactly the same. You've got to hear equipment in person to form an opinion of your own, and 2x 12" SE's are not a major investment. There's a pair of 15"s in the classifieds right now for $290...