With speed, I haven't seen any differences..
I tried with full and as light as possible loads. (no external stuff of course)
Only funny thing that I noticed was exceptional gliding ability which every plane has so far what I've tried.
If there really are some differences in G10 versus other planes, it might be because of some general level FM tweaks.
It wouldn't surprise me, since those planes do glide or retain E better than I could believe.
though, I have no idea how they really glide/retain E.. but gliding 200mph at treetop level for miles....?