I race CX on the bike. I have about 35-40 races over 2 seasons on my current bike (Redline Conquest Carbon). I have played a bit with stem length and positioning. I did find that a 110mm stem (versus my normal 120) flipped up slowed the 'pushing' from the front end a bit. The reason that I did some stem changing was because I was trying to see if I had too much weight or too little weight on the front wheel. Still inconclusive. Just different. The bike is scary fast tho!
The reason I started looking into new frames besides the washing out front end was for something with a bit taller stack. I used to race Ridley (Crossbow) in a 61 (58cm carbon size), but felt it was a bit big and slow steering.
Mind you, I was on the Crossbow when racing Cat 3 for 45 minutes. The move to the 60 minute elite race made a difference in how equipment felt. The Redline did not tolerate getting a bit sloppy since it is basically a crit bike with clearance.
I agree with you, David with the princess and the pea idea too. But I have test ridden almost every bike available in my size and always seem to notice a difference in the feel of the 72 and 73* HTA's. But I rarely have had the chance to race those bikes, which is what is intended. My fear is that I will get the 58cm out of convention of 'sizing down' for handling and handcuff myself into a similar situation, versus getting a more standard fit with the 61 and being pissed I got 2 frames that handle like pigs.
Here are a few shots of various setups over the past few years.
Road bike:
Ridley with 72* HTA, bigger bike, 110 stem
Redline 120 stem (current race setup)
Redline 110 stem flipped up (trial setup)
If it matters, I run 85cm BB to top of saddle. 58cm tip to center of bars, and 73 tip to hoods. ~4 or 5cm drop on cx and 6.5 drop on road. 10cm setback
I notice the shots of the turns, captures the feeling that I get. If i try to drive the front end around the corner it feels like I will have the wheel turned and it will just plow through the turn, so it's almost like I have to let the front end get outside (understeer?) and then muscle it around the turn at the end.