In terms of raw numbers? Of course the PB1000. Has a bigger cabinet and has a fairly wide port for a sub of this size.

To put it briefly, the PB1000 has nearly 6db advantage over the SB1000 25hz and lower. 6db is nearly TWICE as loud. The advantage of the PB1000 carries forward until 50hz with an average of 3-4db more output.
Beyond that, both subs will start to have a similar amount of volume output up until 150hz before they start rolling off.

That said, the PB1000's port tune is specified at 19hz (though measurements has shown that it is actually closer to 21hz). That does mean that below 19hz, the PB1000 has significantly lower output where as the SB1000 with the provision of room gain may actually sound louder. Then again, anything below 20hz requires massive amount of volume to even be usable in a real world scenario - something the SB1000 cannot achieve either ways.

Additionally, some people will swear on their grandma's grave that ported subs are ALWAYS worse for music simply because a ported sub will be "boomier", have distortion or have excessive port chuffing. While yes those kind of issues does exist, they are only present on cheap fart boxes that you pay less than RM1k for. Most decently built subs avoid these kind of plague because they are built to a certain standard.

Have I heard a PB1000 chuff? Yes of course, all ported subs CAN and WILL chuff if you play at obscenely high volumes (and I'm talking about volumes that crack your plaster ceilings). Does a PB1000 ever sound boomy in music? Nope, not unless I place it in an idiotic location. Does a PB1000 ever distort? A little, but the chances of it distorting is very uncommon due to SVS aggresive in-built limiter that in most cases wouldn't allow the sub to kill itself playing frequencies it can't.

So yes, the PB1000 is a better sub. But the more important question is, do you have space for the sub? If yes, go with the PB1000. If not, obviously look at the SB1000.

Dali:
[attachmentid=10747342]
SVS:

read from the page will be easier due to the background color: https://www.svsound.com/products/sb-1000
Maybe you can tell which 1 is smoother..