There are good and mediocre brand name and not-so-well-known bikes. It varies from bike to bike. It sounds like you have a big budget, so think about getting a reasonably priced bike (like my Surly Cross Check). Put the rest of the money in a savings account that you don't touch. Commute for a year, and then re-evaluate your needs. After a year on the road, you will have a much better idea of what makes your ride better.

Then, you can use the Surly on the tough days and your fancy bike when the weather is just right.