My guitars were setup like so:
Fender CompStang RI (setup with 12s and Lace Sensor Red in Bridge)
Fender Mullet-stang(setup with 11s)
Fender Bronco (setup with .10s)
Fender AVRI Jaguar (Setup with .11s)

Observations:
1)The Fender Bronco was more responsive and effective for quick wobbles than either Mustang guitar. The Bronco trem has a more limited range. Bronco kept it's tune very well. The modified Strat arm that came with the guitar sits in the perfect location for quick access but doesn't get in the way of strumming.
2) Both Mustangs were better for smoother, deeper dives than the Bronco. The Compstang with the heavier strings was better suited for quick wobbles than the Mullet-stang with .11s. The trem arm slowly slips down and dangles after a few uses.
3) Jaguar has the smoothest, most versatile tremolo. You can do the suble and deep dives and it stays in tune. The arms stays in place at first, but also drops down after some use.
The Bronco Trem is kinda a hybrid between the Mustang and Jaguar Trems. It has the saddles and trim in one unit like the Mustang, but the single spring design of the Bronco mimics the Jaguar. The Bronco was Leo Fender's last tremolo he designed before he left Fender, but it wasn't used until the Bronco was released in 1967.
Overall, I like all 3 trems. The Jaguar is definitely the best overall, but the Mustang has some definite advantages with the two spring design for even deep dives. The Bronco is great for quick trem, but not as good for the deeper dive bombs.
Post your experiences with your Shortscale trems.