I personally think it depends on what games you're playing. If it's strictly hold em, or Stud, then standard size cards are fine. Now if you're playing PLO or some draw poker variant, it's nice to be able to peel 4 or 5 cards easily(or easier anyway).
Not that you can't with a standard sized deck, but if you think about it, in a 5 card draw game, you're handling 5 cards face down all night, it's nice for you're whole "hand of cards" to be 1.25 inches narrower.
Kind of a silly way of looking at it, but it's just a thought