I love the bike industry. My 2004 Look KG386 has a 25mm post. The only downside (other than limited options at that exact size) is that typical saddle bag velcro is too long for such a small post diameter. I'm happy to see 25.4mm posts because that means with a quick ream from 25 to 25.4mm (frame uses an aluminum insert in the seat tube) I could have some really nice new seatpost options for my 'vintage' frame. I always wanted to justify the Look carbon 25mm seatpost but it was so much heavier than the American Classic post available back then.