Comparing the two androids, which one do you think would be considered more advanced?
Data can probably move faster, is likely more intelligent, and undoubtedly has faster processing speed than the T-1000.
The T-1000 is greatly more durable than Data, is able to shapeshift, can become his own weapons, etc.
Without giving Data any weapons, in a fight, Data would pose as much challenge to the T-1000 as that pudgy security guard in the psych-ward did. The T1K wouldn't even need to try.
As far which is the "better android"/artificial "life-form" Data is far superior in every measurable way.
Keep in mind the T1K was made in the 21st century, presumably either from human 21st century theories or artificial intelligence capabilities likely limited to knowledge humans had come up with by the the 21st century. Data is from the 24th century and presents centuries worth of advancements. Even giving the machines in the Terminator future all of the credit in the world they're not 300 years more advanced than humans.
Data's processors, like all 24c computers, are likely based on FTL nano processors. We've seen that terminators still use things like big, clunky, chips. The T-1000 may be a meta-material based on a nanite-levels of technology but it's still likely hard circuitry limited to processing inside relativity.
We've seen Data as being capable of moving at great speed to complete tasks and we've only ever seen all incarnations of Terminators move not too much faster than a human.
They're likely evenly matched as far as strength goes.
Durability is very much trickier. We see Data take various levels of damage over the course of the series which in even the most extreme cases simply left him deactivated until repairs could be made. Having hard circuitry has this drawback. The T-1000 for all intents and purposes is indestructible but he has limits too. If you follow the logic of the extended version of T2 and BTS information the freezing by the LiN2 and following shattering, melting, and reconstitution was meant to "damage" the terminator. Which is why we see him and his shape-shifitng abilities getting glitchy towards the end of the last act. (In the EC we see him "involuntarily" taking the form of things he contacts, we see his shape rippling and even "processing illogic" like when he imitates Sarah Connor without killing her, in defiance of his programed directives.)
Whenever we see Data take on no-crippling damage we see him recover right away and keep on ticking (the few times he's gotten struck and taken superficial damage he mostly ignores it), the T-1000 when he takes great damage apparently needs to take a moment to reorganize himself. (See: The couple times the Ahnold Terminator takes out the T-1000, he lies on the ground until his body reforms then he moves on.)
So, in a one-on-one fight the T-100 wins simply because he can take greater, almost unlimited, amounts of damage (likely limitless damage in a hand-to-hand combat) and the cutting weapons he can create would likely be very devastating to Data.
In a "which is the better machine", Data wins. If only on the fact he can "evolve and grow" alone.
