Because of the stopping pattern it's hard to say how comparable a 350/730 is, but judging by some small samples in Realtime Trains it seems the 805/807s are about the same as a 390 (which only really covers a similar pattern as far as Birmingham when doing early morning Liverpool or Glasgow service). So arguably no time saving to be had, most likely because Pendolinos are more optimal for long periods on non-stop express running over the semi-fast pattern that Everos are better suited for. I think it's safe to say sub-125mph running isn't really a detriment on the Birmingham route.What is the actual journey time saving for a Pendolino on the Birmingham run over a Class 350, 730 or similar? A Class 730 is 110mph and, I think, has every axle motored. It certainly accelerates quite rapidly anyway!
For those who can't see the images, the first two are Pendolino diagrams (0616 to Liverpool via Birmingham and 0716 to Glasgow via Birmingham respectively), and the third one is an Evero diagram. All show a departure time of xx:16 and an arrival of xx:48 about an hour and a half later.


