Which stabilizes a carbocation more : Back Bonding or Conjugation? Suppose we take these two compounds:



The first carbocation can rearrange to produce the second one by hydride shift. Which is more stable ? Why ?
I am inclined to consider the second one as a "bona-fide" carbocation, if that makes sense. The first one resembles a protonated aldehyde rather than a carbocation, so relatively speaking, the first one should be more "stable".