You got me by a couple, but I still remember my first detector. It was an X/K also! I bet not many of us remember when that was 'state of the art'. Some people will tell you Valentine is the best. It probably is for many reasons, upgradeability is one of them. However.....as far as functionality is concerned, I think some rival it. I know from personal experience, the Whistler has better range and reaction time than the Unidens. Whistler gets pretty damn good reviews. I just retired the Uniden in the back window and put in another whistler, but a cheaper model. My 1660 in the front window is a couple years old now, but still saving my butt! I can't bring myself to retire it until I find another with a sexy female voice that talks to me. It'* pretty cool!
I doubt the 1660 is still available, but it'* got a text display and voice. If I recall it was just over $250 new, but the price dropped like a rock a couple months after I bought it. I've read a couple reviews that put the Whistler above the escort series, too. Pretty impressive considering the way escort backs their product.
I've been custom wiring all my detectors for years now. I hate fiddling with the little switch up on the detector. I run my detectors off a switch on the console. Gives my co-pilots something else to help with, too! That way if you DO get pulled over, the cop won't see your cord, and won't see your arm go up to turn off the detector. Mount it high enough, and he won't ever see it.