I'm a bit tired but I ran some numbers to satisfy my own curiosity. They are rough but reasonably accurate.
Measured Item Riggio Cannondale
Seat tube, c-c 50 cm 48 cm (it's a "52 cm")
Top tube, c-c 52 cm 52 cm (it's a "53.5 cm")
Head tube length 11.7 cm, 16 w/hdst 12 cm
Chainstay length 38.5 cm min, 39.5 cm 40.5 cm
Saddle-BB height 67.8 cm 67.7 cm
Stem length 14 cm 13 cm
Stem drop, approx 2.5 cm 0 cm
Bar width, c-c 39 cm 40 cm
Bar drop, approx 18 cm 15.5 cm
Front center (BB-hub) 56 cm 57 cm
Crankarm 170 mm 170 mm
BB drop, approx 5.2 cm 6.5 cm
Wheelbase 95.5 cm 97 cm
Seat-bar drop, approx 28 cm 25 cm
Seat center to drops 82 cm 77 cm
Some of the values are approximate since I don't have a super accurate way of measuring certain things. One measurement is variable - the track bike's chainstay length (BB to rear hub) differs based on chain length and gearing (you move the axle to take up chain slack). Currently it's 39.5 cm. If I went to a 52x15, I'd shorten it by 0.5 cm. A 53x16 may not fit, or it would put me at my minimum 38.5 cm (and make it virtually impossible to get the wheel in).
The huge differences are in the "aggressiveness" numbers - wheelbase length, chainstay length, BB drop (or lack thereof), short front center, and big saddle-bar drop. All are different by a centimeter or more, unusual for such critical frame specs. However the difference between track riding and crit riding is also different by such magnitudes, and the bikes simply reflect what works for what.
Interestingly enough the Cannondale is a very conservative race bike. It's equally at home on long rides, steady climbs, and harrowing descents. My first (racing) road bike had a much shorter chainstay, I think in the 38.x cm range, the same length as the minimum on the Riggio.
This means the Riggio is also a conservatively designed bike. Although it has some steep angles (long ago I used a protractor and convinced myself I had a bike with a 74 degree head tube angle and a 75 degree seat tube angle, but I think this is about as accurate as a day dream) it's otherwise a very forgiving and easy riding bike. My ham-fisted handling of the bike never put me in the pavement nor did it ever freak out on me. The only thing I wish it would do is turn faster in a full sprint.
For now though, like all the problems I have with the Riggio, the main issue is the nut that holds the seat down.
Once I get that working reasonably well I should be all set.