I've driven all three models in the summer (70D, 85D, and P85D). The power difference between each one was very significant. Although the difference between the 85D and P85D in sport mode was very close. I eventually chose to get the 90D model because it had in my opinion the best bang for the buck in performance and range. I'm a performance junkie with my two previous cars being a 2013 GTR and 2008 V8 M3, and I'm more than satisfied with the power of the 85D/90D. The 70D on the other hand was noticeably slower. To me the price difference between the 70D and the 85D is worth it on the power difference alone, but since I also got significantly more range, it was a no brainer.
But one decision I'm having second thoughts about is the decision to upgrade the battery to 90KW. My brother got an 85D shortly after I got mine and the range difference between our two cars is only about 18km. I'm not convinced the extra $3400+ is worth it especially considering there is no performance improvement. I'd rather put that money towards any of the factory options before upgrading the battery.