20 miles each way here with no shower, easy in, hard home seems to work. I tend to do a 14-14mph average on the way in and 16-17mph on the way home. I’ve got a stick of Mitchum at work for a bit of pit freshness before I put my shirt on.
As others have said, no luggage is crucial (for me anyway) so I use a carradice Sqr bag and tend to dress a bit cooler (temp wise, there’s nothing cool about fluro jerseys) than I would if I was going for a leisure ride to keep the sweat down.
I’ve had no complaints at all, and my office is pretty small, I don’t even bother getting changed in the toilets any more, just get naked in the filing and hope for the best.