Not pushing the XT drive, because you know what you want: Between those 1TB drives and traditional 750 GB 7200 RPM drives, there wouldn’t be a difference. The 8 GB of flash memory used as a cache would be the big differentiating factor, making it actually have a perceptible impact on performance once it learns your usage patterns. It’d be faster than the 1TB drives listed above.
All that said, you know your desired capacity, and you know your budget allows for a choice of those drives. Maybe check to see if there is a difference in warranty; if so, let the warranty be the differentiating factor instead of a ~5 MB/s sequential speed difference (which translates to very little difference when reading lots of little files, as both drives are tuned for consumer applications). If there is no difference in warranty, check sites like Tom’s Hardware for reviews on each and see which drive does better at what you usually do. Those in-depth reviews show differences in drive tuning that actually affect performance in some applications.
Also check to see if there are any helpful-yet-annoying features that either drives has. Example: laptop drives frequently park the read/write heads (lowers power consumption while raising shock tolerance and overall reliability except for head loading/unloading cycles). Occasionally these drives take a perceptible amount of time to wake up once they go into a lower power state.
If annoying features/bugs exist, read up on them now and see if your configuration supports a fix. Maybe check to see if there is a way to change the drive’s internal power saving parameters. These things will not necessarily be covered in full-length reviews on dedicated sites, but you might be able to find clues from user reviews on retailers’ sites. You may also glean this information from the manufactures’ forums, where long-time owners will flock to complain about bugs in the hopes that a firmware update can solve it.