So I owned the I-Pace for about a year and traded it for the e-Tron which I've had for a month. I guess I have a different take on the cars than Graham, but that's what makes horse racing.
My I-Pace died in the 2nd week of ownership and had to be towed to the dealer. Fortunately it wasn't a major issue, and I had no major problems since then. However my Vin# was one that would require a tear down of the front end of the car to replace a wiring harness. That made me nervous since I had little faith the car would be put back together without rattles. I had many software issues with the I-Pace that manifested itself in different ways with the main center screen. I would periodically lose the radio or the display itself. Some of these issues were similar to those I had in my Tesla.
My other concern was the financial solvency of Jaguar, the apparent 'lesser half' of Jaguar/Land Rover. Jaguars, and more specifically I-Paces, simply aren't selling here in the U.S. They're never advertised and in one year of ownership I saw exactly one other I-Pace in my travels. Tata motors doesn't seem to be willing to spend much money on Jaguar and the British government certainly isn't either. Those days are gone. So a combination of these issues & concerns, together with the results of an e-tron test drive, convinced me to trade in the I-Pace.
Thus far the only software issue I've had with the e-tron is receiving multiple notifications that my charging is complete. Audi just fixed that in a software update of the app, but I believe a problem remains with a charging cycle that apparently goes from 79% to 80% and then back to 79%. This is the issue that causes multiple 'charge complete' notifications as the charger keeps bringing the car back to 80%. The issue can be avoided by charging to 100%, but you don't want to do that with any frequency. It seems that not everyone has been experiencing this with the 2021 e-trons, but some have, Other than that the car has really been pretty much perfect.
I agree with Graham that the I-Pace is more of a 'driver's car' than the e-tron, but I'm at any age now where I more appreciate a smooth, controlled, quiet ride than one that gets me from 0-60 1 second faster. My first test drive of the e-tron showed a stark difference in ride comfort & quietness. The sound insulation from road noise is worlds better in the e-tron than the I-Pace. In fact there's no doubt in my mind that the e-tron is the quietest car I've ever been in. I believe it was Car & Driver that said the only car they drove that was quieter was a $355,000 Rolls and that was only by 1db.
Now interestingly, my range experience, although granted only for 1 month, is quite different from Graham's. I'm actually finding the range on my e-tron to be equal to or better than the I-Pace. My latest range at 79%, showed an expected GoM display of 199 miles. That's about 240 miles at 100%. The e-tron seems to do better with highway range than my I-Pace did. All EVs do worse on the highway, but I always saw a more precipitous drop on the highway with the I-Pace than I have thus far with the e-tron. I also find the GoM to be more accurate than it was in my I-Pace.
As Graham said, you really need to drive both cars to see what best fits your needs. We all have such different tastes, that it's impossible to say what's the 'best' car. These are two wonderful cars and it's hard to make a wrong decision. Good luck!