Smooth Twist X versus "regular" ST and LW? Rigidity, not accuracy discussion...

This may be as good a subject as any to ask the question. Compared to a standard Smooth Twist barrel, is the Smooth Twist X barrel liner in outer (shroud?) as stiff (resistant to bending), both elastic and plastic deformation? And how would either compare against the standard LW barrel? The liner itself appears rather fragile, but perhaps the outer barrel shroud (?) is as stiff as a regular non-two piece barrel system? I don't have the X, but I do have guns with ST and LW barrels...
 
"Macros"Interesting question. Especially since reading some of the posts lately, I highly doubt the ST or the X are anywhere near as rigid/strong as a solid barrel, especially the thicker ones. Anyone's guess how they stack up to the skinny air arms ones, but they have barrel bands.
The ST barrel is a solid barrel, the last few muzzle inches is the only part that's thinner. 14mm diameter on my Royale in .22 and .25.