Wow.. talk about squeezing the oxygen out of your lungs Steve.
I mean, I am a 'big and fat' guy and I run 23in on my gearie 26er bike. I had tons of confidence problems in tight areas when I started riding so I went down to 23 and no major problems since. One year later, I buy a SS29er and I only cut a bit down to 24.5 inches. I can't belive the difference. I do feel more stable and easier to pull the bar to turn with the extra 1.5 inch. I also don't feel as crampped. I get on my 26er and I feel squeezed and cramped. The geometry of the bikes are totally different so that has a lot to do with it.
If you have the "long horns" type of bar and want to get down, cut a little (.25 in) at the time on each side and test it. the smaller they are, the more force you need to turn but easier to get through tight places at faster speeds. If you have a SS bike with 29 inch wheels, don't cut too short. Leave a bit longer for the big wheels. If you only have one bike or more then one with same lenght on the bars, you get used to it. Is when you switch from smaller 2 larger often or viceversa that you notice the difference.