There's no doubt that this year's Surface Pro models are significantly faster than the last generation since Kaby Lake-R doubles the number of cores from Kaby Lake. The bigger question, however, is how much or little the models will throttle when under load. Performance throttling was abysmal on the 2017 series and it's just slightly improved for this latest generation.
https://www.notebookcheck.net/2018-Surface-Pro-6-series-still-suffers-from-steep-CPU-throttling.354206.0.html
Jeez I wonder why.
*Looks at passive cooled i5 in a tablet* Such an unecessary trend, considering you don't hear the fans when doing light stuff anyway.