Well, as you know the idea of PR's is to get the effects of porting with a smaller box, with a powerful sub like the Maelstrom, this works because you don't need a large box to get the free output down low, the motor handles that. If you can't tune the PR's low, then there is no point to using them, a port will do. In this case, ports can handle everything up to what the PR's do with upto 850 grams of mass (8" port 36" long) now if you really drive the maelstrom hard, it will chuff that port, however, your PR's will also be giving out at these outputs as well so the comparison is pretty equal. Where things start to get fun is when the PR's make a box/tuning combo that is simply unheard of with a ported design, the rules are fudged around 1200grams, stretching things nicely in favor of PR's, but the added cost really makes them a toss up with that kind of added mass. When you start to add 1500-2000grams is where things get really fun, which is why I asked. The deeper you tune, the more of the Maelstroms excursion you can utilize with a given input power/box size, you don't want to have to spend more on your amps than you do drivers, so $700 options like the XTI4000 are impractical for many people. Your other option to utilize this excursion is use a larger box, but lets face it, we are using PR's we don't want uber boxes, so the only way to use that excursion is with a deeper tune, deeper tunings require more mass though, which continues the downward spiral. (I'm not telling you this so you need to know, Kevin, just so others will fallow my train of thought)
The sweet spot for this combo looks to be around 1600-1800g of mass on the PR's.