According to the early Antutu benchmarks, apparently the CPU score difference is very little, and the extra core of the graphics is providing %9 boost compared to the 2018 models.
source: https://www.gsmarena.com/apple_ipad_pro_11_2020_shows_9_faster_gpu_on_antutu-news-42104.php
The benchmarks doesn't mean everything but still, they are informative. So just based on performance, i wouldn't update an iPad Pro 2018 unless i am someone using the hardware on it's limit. I don't know if the 2 gb ram will make a big difference today but most probably will make it more future proof. I still have a 1st Gen iPad Pro, now trying to decide if it is better to go with a 2018 iPad pro with discounted price or the 2020 iPad Pro. Guess i will have to wait to see some deals on the 2018 models.
source: https://www.gsmarena.com/apple_ipad_pro_11_2020_shows_9_faster_gpu_on_antutu-news-42104.php
The benchmarks doesn't mean everything but still, they are informative. So just based on performance, i wouldn't update an iPad Pro 2018 unless i am someone using the hardware on it's limit. I don't know if the 2 gb ram will make a big difference today but most probably will make it more future proof. I still have a 1st Gen iPad Pro, now trying to decide if it is better to go with a 2018 iPad pro with discounted price or the 2020 iPad Pro. Guess i will have to wait to see some deals on the 2018 models.