Fred, here's my $.02 ...
There are better ways to spend your money, and I really like the idea of a surprise gift for the wife. There's no better way to spend money than that!
Having said that, and assuming that money is absolutely no object, I can see some benefit from one. Keep in mind that everyone speeds... everyone. We don't always mean to speed, but the throttle creeps up and down, and you never know when you're going to go just a little too fast for the "acceptable" speed in that area. Acceptable = safe speed for the conditions. If you are using a radar detector, and you are paying attention to it, you'll slow down when it starts yelling at you. Mission Accomplished. You slow down, stay a little safer, and the nice officer doesn't have to take a motorcycle collision report. Everyone wins. The ticket doesn't matter to the officer... Another speeder will be along shortly.
Make the decision that's best for you. It doesn't sound like you need one, but it's your money. Enjoy it.