Just curious since I've tried a variety of frame sizes now and can't really tell a difference? Seems like folks often say how a good fitting can really help or having a bike sized perfectly... my first road bike last year I bought used off craigslist knowing nothing about bikes. I don't really have a LBS (depending on your definition of 'local') although I did travel to a couple in the past but after seeing the prices decided I wouldn't be shopping for a new bike or a fitting.

And then this year I picked up 2 more bikes, each a different size frame and they all feel fine to me.

The LeTour is 23" frame
The Tempo is 22" frame
The Prologue is 21" frame

I go back and forth between the LeTour and the Prologue frequently, and have been over 50 miles on the LeTour and I think close to 40 on the Prologue and they both seem comfortable to me. Maybe still being a newbie I just can't recognize the minor differences? Or perhaps maybe on a longer trip the difference would be more? This year I really haven't had the chance for anything long but I would like to ride further some time in the future. But its a safe bet that 99% of my biking is under 50 miles for a while, at least for a few more years until my son is old enough to stay at home by himself. Though I do want to maybe try out a duathlon next year on the Prologue which I heard you typically go down a size or so on a race bike which is partly why I went as small as I did on the Prologue.

There is a range of fit for everyone, changing a frame size up or down by an inch can be compensated for by changing the stem length to match your preferred reach... I suspect that the 22 is the ideal size and moving up or down and inch and adjusting for top tube / stem is what makes this work.

I normally ride a 55 cm road bike but can also be pretty happy on a 52 if the top tube and stem compensate.

True that more miles make you more sensitive. Both miles during the ride, and total miles ridden. The time to look for fitting is when you feel you need it, which often comes after discomfort or hitting performance barriers.

Schwinn in the old days sold bikes in 2 inch increments, not 2 cm. My Super Sport is the same size as your Le Tour and maybe a little big for me, but with big handlebars and turkey levers it's easy to sit on.

The LeTour is tall enough I can barely stand over it, it does touch the crochey parts but as long as I do not dismount into a big recessed area it's not a problem. The seatpost is just about buried. But it feels fine to ride and I've done the longest runs on it actually. It is perhaps a little less comfortable to ride low in the drops but that is partly due to my inflexible lower back. I rarely ride in the drops on it. On my Prologue I can ride in the drops or layed over on clip on aero bars but I have to tilt the seat down a little to do so.