What's wrong with bigger?

If I had to come up with a rule of thumb for people shopping for a bike it would be something to the effect of: whatever size bike the shop puts you on, at least have a go at one size up. There will be plenty of occasions when the next size up is too big, but with my adjustable fitting bike I rarely have a negative response when I adjust the bike to the next size up for a client. Usually the response is “what did you do? I like that better.” On occasion it has been two sizes bigger. Yup, two! Read that again. The proper, comfortable and best performing size for the person sitting in my workshop was two sizes larger than some shop had decided he needed. Yikes.
There are exceptions to this. I managed a bike shop in Canadia that had a rule – every bike on the floor had the bars as high as possible, the seat as low as possible and each customer was sold the absolute largest bike they could get away with. The only time I’ve seen such an approach go awry is with growing kids when they are handed a new bike that is actually larger than they can safely ride now, in the hopes that it will fit them well after their next growth spurt. With fully grown adults, no one ever comes back to the shop and complains that the bike is too comfortable.
Cadel Evans is a low-bars kind of guy. Particularly in his TT bike, but also in his standard road bike. He is by no means unusual in the pro ranks, but we do not follow Mark Webber’s seating position in his Red Bull F1 car with our road cars and there is a similar case to be made for not following a pro cyclist in their position on a road bike. Cadel’s office is the road bike. He sits at that desk many hours each day for about 46 weeks of the year. Many recreational cyclists ride as far in a year as Cadel and his co-workers ride in a week (or a month for the more eager amongst us).
One of the variations that you have to take into account with bar height is bar reach. If I take your existing bike and move the bars higher the reaction I often get is “the bars are too high now”. If I move the bars further away from the seat a similar amount to what I moved them up, this is when people start feeling really comfortable.