Just wanted to add another major advantage of the cartridge tips (metcal/JBC/T12/ADS) vs old ceramic heater styles, so's I'm not trying to say they're the same in every regard.
They are way better for using sleep stands. The 888 style tips need way more mass of copper to work properly, so will cchange temp slower. So if you run temps/tips where you benefit from sleep and are frequently in/out of the stand, then cartridges will provide a major advantage, which should provide longer tip life under these conditions, and faster operation out of the stand.
So, for many people the Metcal is going to be better. And in exactly the scenarios they imagine. It's the common reasoning of the how and the why which I disagree with. Once up to temp, this "responding faster and dumping more heat faster" thing is not actually the case (in any significance) how I understand it.
The RF Curie deal does not do anything to correct the sag between base/sensor copper and tip copper (and this is the sag that matters). What it does is make it faster to raise and lower the entire saggy bed, between sleep temp and the sliding scale of fixed set temps that compensate for the tip type. Same for pretty much all cartridge tip irons, but with those others, you have to jack up the dial, yourself.
(For me, I have almost zero use for pokey tips, or protoyping of multilayer boards, so I don't need to use high temps/sleep. Even if the pokey tip provided insta result and didn't require more frequent wiping/cleaning, I would still gravitate towards the largest tips for the job for the way they interact with and handle solder.)