I have the double strada and my wife has the strada wireless. I also have a wired strada on my second bike. Some people report unreliable signals caused by interference, but we have never experienced interference.

I find it frustrating to link the double strada speed and cadence sensor to the computer. It never seems to work as the instructions indicate, so I end up just messing around with it a bit and it magically works. I like having the cadence, but if you don't want that feature the strada wireless is a lot easier to setup. Both seem to be reliable and I like the small size of the computers.