I'll weigh in on some of the same points…ergonomics is good on the t2 but NOT nearly as good as I expected. Ergonomics to me pretty important as I have some back issues that also affect the shoulder and neck but I don't find the t2 vastly superior. It's not much better if any than an AT Pro/gold with a 5x8 coil IMO. The small coil on the t2 obviously improves ergonomics more.
The headphone jack to me is also a non issue. I run a 1/4" adapter on my ATP and it exits under the arm cuff just as the t2 so it's all the same to me.
Coil swapping on the other hand is hands down easier on the t2. No comparison! I keep the 5x8 coil on the ATP as it works really well, balances nicely, is still plenty deep and really have no desire to swap it. Thank God because coil swaps are a PITA!
Performance…I'm not seeing much of a difference. I id'd a target in my yard last night using the 5" coil on the t2 coming in 80's one way and 50's-60's the other. Depth indicates 8-10". Today I put the large coil on the t2 and checked the same target. Signal came in more clear but getting same numbers. I also checked it w/my AT and am getting a nice smooth high tone one direction and a nice mid tone the other. The tones on the AT are much much smoother and way easier to read. I can definitely tone hunt with the ATP and am very reliant on the screen of the t2 to determine whether I wanna dig or not. But I do have WAY more time on my ATP and and just starting using my t2. As for the target…both machines are id'ing it the same. 8-10" high tone one way, mid tone the other. I'll let ya know what it is after I dig it.
If I had it to do over, I guess I'd have opted for the AT Gold. Only because I'm very familiar with the Garrett AT language and VERY comfortable w/it.