Needless to say, I had a lower grade Cobra 9940 for about 6 months and I just (three days ago) got my STi Driver.
I haven't been able to really test it out or do any serious driving as of yet however I have a few gripes. This is going to sound silly but, I'm actually missing some of the features that my cobra has! For starters, the cobra had a screen that would only come on when it was detecting radar to show an alert. So the majority of the time it was black. However with the STi Driver, the display stays on ALL THE TIME unless you go into dark mode. This particular option with the cobra really helped when I was listening to loud music and could not hear the alert tone, especially at night, it really grabbed your attention when you were getting radar, because you saw it only when it was detecting something.
Second, The cobra also had auto off as well as low battery power down protection. This was great! You never had to power down or unplug your detector when you get out of your car, it shut off in 5 minutes or if the battery went down to a certain level. This is something the STi doesn't have.
Third, The cobra had a battery level monitor. It may sound silly if you have never had a detector with this feature, but for me I found it very useful. I do tend to sit in my car and have it off while listening to music alot. with a touch of a button I could watch my battery current and an alarm would sound off if it ever went below 11.something volts! Another thing the STi doesn't have.
Honestly, to me I feel that a $400+ detector should absolutely have these options, really. I'm not trying to put down the STi I am very psyched to have upgraded to such a fine unit, however I have just gotten so accustomed to having those options! Please feel free to comment on what you think about all this and get me more psyched for purchasing this detector