The only reason opposes me is that my wife and my mom and my dead are going to kill me, for they are already unhappy now. Well, and $140 more monthly loan. In the first glance, $10,000 for the Deadline to make the change: Jan 2nd. Pros: 1. Confidence on road trip. 20 miles range left when arriving on a SC is much less anxious than arriving with 5 miles left 2. Higher charge speed at SC 3. Higher driving speed with confidence because more range 4. Longer battery life. As others suggested before, 8 years later the battery degrades to 90%. That is 231.3 mile for the 90D, while 213 miles on 75D. That 213 range is not very useful. Maybe not able to complete some road trip without annoying super long charge time. 5. Spontaneous trip: for some trip you might need 75D to be 100% charged, and with 90D you might be able to go with whatever range you have after coming back from the office. 6. Higher acceleration: might not ever really be used, but for occasionally showing off 4.8 sec is much better than 75D's 0-60 in 6 sec. And since you own a Model X, people might come to you and nudge you to show off quite often. PS. Do you guys think the $3300 interior upgrade worth it? I already add PUP but that's mainly for the HEPA and the ventilated chair.