As far as which can handle more power, I would assume it greatly depends on at what frequency. At/below tuning on a ported box the sub has ridiculous amounts of excursion, and for those frequencies I would say a sealed box would have better power handling because it would dampen the sub. At frequencies above tuning I dont really have any guesses for though...
That link was interesting, saying neither is better. However, it is not everyone's goal to achieve a flat in car response. Sure that would be nice, but some of us, like me, just want a decent response with as much output as possible. In this regard, ported wins hands down, or at least some variation of ported. A sealed box needs a lot more power to have the output of a ported box, so whats the point? For output purposes a ported box is much more efficient and in a daily setup that is what we all want.
I guess thats all I have for now
the bold is true if you want max output imo. that link i posted was from an sq-oriented forum so most of the members are leaning in that direction.
if we're going to discuss power vs output, where IB? most normal setups featuring 2 12" drivers would be cool running off 300 watts between them. i'm strongly considering doing that with a car that i'm going to keep for a while. in the mean time...messing with a deathbox might be fun.
lets take into account what "daily" means to most of us...usable trunks, perhaps? not spending hundreds on electrical system upgrades? honestly...your box takes up the entire space back there. and how much does it weigh? for max output, yeah, ported is the way to go. my box's airspace is 21" wide, 11" tall, and 6" deep (plus some "fairing" added to hide the amps and stuff)...its tiny. add some polyfill inside...bam...up to a ~.7 cu ft space.
i like audio equipment (had a system in my car(s) since 6 days after i got my license) and i've adopted the "golf bag" rule. cant fit my bag in the trunk...wont take up that space with subs. even with 2 12" subs in my small first car, there was still room for 2 bags in back plus one in the backseat so 3 of us could go at the same time.
the reason we want flat response is so that those of us who dont listen to 20-50Hz "music" wont have a huge spike in the curve. my box doesn't have a tuning frequency. hell its crossed at about 110Hz because i dont need extension under 50Hz very often...so its senseless for me to give up response up top trying to make it play low. its sacrificing some low but honestly...the music i play rarely has some extremely low bass guitar notes in the sub-30Hz range. even if i do play something with some bass, my sub can still go low and love every note under 50Hz. there was a spike around 60Hz without polyfill, and that was eliminated almost instantly. setting the crossovers and gains correctly means the bass is punchy and some songs, recorded just right, are like a punch to the chest...even with less than 600 system watts...yeah...total.
if i move up to a 600 watt amp, i dont think id need much more for the bottom end
so there you have my opinion. an ideal, perfect, flat, and physically small ported box would be the only way one would make it into my car. yes ive had ported boxes before, yes they were in my car. the deathbox would be the only ported box id even consider looking at, although i need to do some more reading about it.
"music" was in quotes before because some people actually listen to real music and enjoy hearing all the recording...not just have ours backs bashed with bass. high school was a good time...
sorry to anyone who didnt like it 
