How did your old bike get stolen?

I usually build my bikes up myself, although my newest bike I bought new, mostly because the secondhand market for folding bikes tends to be a bit overpriced.

I have also noticed that bigger bikes tend to be more stable at speed, they usually have a longer wheelbase, and more relaxed geometry.

Your Cannondale should be quite stiff near the headtube and bottom bracket, this generally makes them feel more responsive, compared to most other bikes I have ridden.