Are you kidding me? JL yeah definately, but Alpine Type R 12 sub is about the best bang for your buck you're gonna get broski. Actually I can't honestly think of much better than those 2 brands either.
Can't think of anything JL excels in... SPL they get smashed by your typical Sundown, DC, AQ, Fi, IA, Crossfire... SQ they get smashed by Arc Audio, Rainbow, DLS, Focal, Zapco...
Alpine makes a solid headunit, thats about it. They have good bang for your buck speakers/subs around that price, but for a little more you can get a whole lot better.
OP, ignore this guy and all the people that are actually picking between those two brands.
For 1000 watts, you can get the AQ 1200D for a whole lot cheaper. Plus, you can talk to DJ, the owner, if you need help. As far as subs go, the AQ SDCs are actually a fine budget choice, along with Sundown SA series, and DC Level 3s are great for the price too.
There is no such thing as which will be better for SQ or which will be better for SPL. It's solely going to depend on your box and your vehicle. I can guarantee I can make cheapie walmart subs sound better AND get louder than those JLs and Type Rs if they aren't in a good box built to spec.