A 73 degree head angle is very standard for a road bike. The seat tube angle is a little steeper, but saddle position on the rails can compensate for a degree either way (0.8 cm fore and aft). Handling is affected by many things; one of the most important being weight over the front wheel. This is determined by reach (distance from BB to head tube). A shorter reach and longer stem will put more weight over the front wheel, and feel more secure. A longer reach and shorter stem will feel less planted because your weight may be up to 2cm further back – despite having exactly the same relative position with regards to saddle, pedals and bars.
Based on your current bike, which I assume fits, and may have a 100-110 stem, I’d infer you were approximately 179cm with average proportions, you can go down a size to a virtual top tube of 54.5, and add a longer stem, or pick the same again. I have bikes with 72.5 and 73 degree head tube angles. There isn’t much in it to be honest. I do however prefer a slightly smaller frame and longer stem because I think the handling is better.