Frederik is correct. I have an Express (long story about how I got it, but in short wanted a 458 WM/Lott in a Brno/CZ action, to build a 450 Rigby. Now a few years later, I can honestly say, I am very satisfied with the Express. Similarly with the Lott and the WM.
It is true, with the lack of powders year ago the Express was created, resulting in less pressure and recoil. This is the beauty of the Express and maybe the Lott over the WM, it gives you that extra room, for a bit more slower burning powder. I am not a reloading expert; but someone explained it once to me (maybe someone can put it on here) the consideration of Load ratio...maybe a discussion for another thread?
@CoElkHunter we did once experiment with the 458 Express and the extra room and loaded it per spec with faster powder. I cannot recall the detail, but it was a 500gr at 2300+ and boy did it have a punch.
Imho, a Lott / WM / Express all have the same felt recoil - it is not a jump between them like from a 375 to a 416 etc. Then again, my 416 Rigby feels to me it has more recoil than my Express... I personally have no issue with either a WM/Lott/Express/Rigby - only with a 460 Weatherby