Do you ride a Bosch?
I have had a Shimano, and a Bosch, and basically don't notice any difference over 25Kmh. The difference is so minimal it doesn't really count in my opinion.
Yes, I have a Bosch Performance CX. I think the lag at 25km/h is very noticeable on roads as much as even making my forks dive a little, less so on trails.
However, I love eMTBing so much that I'm ok putting up with it. I don't know how Bosch compares to other motors for lag, but from what I've read, it's very laggy compared to e.g. Brose.