I have the Escort 9500ix (and the Escort X-50 in other cars) and they work great.
I do have to say I frequently pick up laser signals from cars being scanned ahead of me.
So yes you can pick up laser before it is too late. Nice thing about laser it the user must be parked and in clear sight. Remember a detector does not give you a free pass.
BTW Escort has a nice remote control cord available the allows mounting in a easy to see spot and a mute button so you are not reaching up to silence an alarm. The GPS feature is also very handy to shutdown regular signals from doors or whatever.
I have detected signals from approximately 5 miles away on the Escorts, so range is among the best.
Valentines also work well but just look like they fell out of the '70s. IMO.