Irrelevant, explain to me how you would send $25 / 0.25 BTC to a friend without being forced to use IOUs in Ripple.
Meanwhile, with bitcoin, sign a transaction.
If you're talking about someone that has a bitcoin wallet and just wants 0.25 BTC then the comparison you should make is with transferring some amount of XRP which is ... sign a transaction.
But you mention $25. And since you like to ask for rhetorical explanations: Explain to me how you would send $25 to a friend using bitcoin. Not $25 "worth" of bitcoin but $25. If at any point an exchange is involved then you're using IOUs at the exchange.
There are numerous differences with XRP/BTC, most importantly the fact that you still need trust to send XRP transactions (the whole ledger system is based on trust), and there's also the distribution.
So what if an IOU is involved in an exchange? I'm not going to have that IOU randomly substituted for something else because OpenCoin Inc places having a flawed system that somewhat works over not making me lose money.