OK, I'll give it to you from an Xterra owner's view.
First of all, I'll start out with the fact that I know virtually nothing about the T2, so I'll not speak to it at all.
The Xterra is a remarkable machine. Comparing it to any other is tough, due to it's unique technology. There simply aren't any others out there incorporating Vflex chips. The ability to change to any one of three fixed frequencies on one machine by doing nothing more than changing coils, is not only unique, but economical and extremely practical as well. The only other option is having several dedicated detectors, all of which have their own learning curves, and all told will cost a small fortune if all are of the similar/same capability level.
The Xterra is super easy to use. Or as complicated as you want. Almost everything can be done automatically, or manually.
Sensitivity, Threshold, volume, number of tones, and GB Offset are all manual only controls.
GB Tracking, Target ID Stability, and Beach Mode are all either ON or OFF.
You have a choice of PinPoint Auto or PinPoint Sizing.
You have four Discrimination pattterns available. All of which can be user modified. And the machine remembers them. ID segments are from -8 to 48 in two digit notches totaling 28 ID segments. In Multi-Tone, each of the 28 segments has it's own tone. You can of course choose either one, two, three, four, or Multi tones.
If you're a prospector, then you'll like the Prospector Mode w/Iron Mask. No ID, but it is true no-motion all metal.
Then there are coils. The 6" and 9" coils are waterproof. The others are only considered water resistant. There are currently four different High Frequency, three Medium Frequency, and one Low Frequency coils available from MineLab, as well as a CoilTek 15" WOT MF and a couple clandestine coils from N.E.L..
Oh, and my 705 was Made In Australia. Many were also Made In Ireland.