My dad got the while K40 Calibre system with front and rear laser shifters as well. It has only been 6 hours since he picked up the car, but it seems to work good so far. Here is a closeup to where the installed placed the front laser:
http://www.supercars.net/pitlane/pics/3325786e.jpg
Know, I wouldn't even consider the Escort Passport SRX because they replaced it with the Passport 9500ci, which is a lot better than the SRX. Personally, I would get the 9500ci over the K40 Calibre, as the reviews I have seen online say its better, and it is cheaper, but when my dad called a few local K40 and Escort 9500ci dealers, they all recommended the K40 system and said that those online sites are payed by Escort to give them the best reviews, so he got the K40. I am sure the K40 is fine, but is costs almost a grand more if you want the same units, and it doesn't have a display or GPS (which warns you about incoming popular speed traps and speed/red light cameras, and if the system reads the same signal four times in the same place, it learns to block that signal, so there are very few false alarms). The K40 does have a separate rear radar detector, which is a nice benefit. Finally, the road off the road we live on has a perminant "Your Speed Is: XX" sign, which uses Ka band radar to detect cars speed, but we noticed that the K40 Calibre recognized the radar later than his Valentine 1 in his Benz does, which may be attested to the fact that the radar used in the sign is really week, and the K40 is trying to weed out false positives, but it could also because it can't read the signal that well (the sign is right after a curve along a heavily wooded road). Once we drive it more, I will make some more notes about the Calibre system. Anyways, as far as your question, I would go with the Passport 9500ci. It is what I am going to install on my Audi S5 when I get it a week from tomorrow.