The X1 does not offer docking stations nor does it offer the port range that a T460s offers (full ethernet, card reader, etc). The T460s is a few mm thicker than the X1 and about 200g heavier, but it shares a lot of hardware with and can use the same dock as the X260, T460 and T460p which is interesting if you're a business customer that wants to support a range of options from ultra-portable to powerful.

If you're a single freelance person or consumer, the X1 may be the more appealing choice.

The X1 has soldered on memory. And non-user-serviceable batteries and hard drives. (My 1st gen X1 carbon used a very non-standard hard drive.)

The T460 has hot-swapable batteries, real memory slots, and standard SATA disks. (but I wish is was a NVMe disk)

I picked a 460 over a 460s because it seems a lot more servicable in the future and I can easily replace worn out batteries.

The X1 has strange RAM config options and was way more expensive I think.