Speeding is worth it if you have a ways to go or want to stay awake & alert.
I used to drive vehicles that rewarded good driving (Ford Escort GT, Audi 4000). Nowadays I poke along in a Nissan pickup, so speeding is not nearly as gratifying. Also, I live in DFW, where the unofficial speed is the limit+10mph. I generally go 10mph over on the highways and get passed by Tahoes and F-150s all day long. I don't need a radar detector in DFW. No tickets in 5 years, either.
I generally was a more attentive driver when speeding, constantly surveying my environment both to safely maximize my speed, given conditions, and to keep my eyes peeled for revanue collectors. Nowadays, when I poke along at the limit or a mere 10mph over, I am usually in "Sunday driver" mode.
There are some tips to safely speeding, especially on the highway, one ought to take into account:
1. Get a quality radar/IR laser detector and understand how it functions.
2. Do not mount it "front & center" with the curlycue power cord in the windshield, unless you want everybody on the road to know you have a fuzzbuster.
3. Mount it in the lower left-hand corner of the windshield with a quick-takedown-type mount, for when you need to get it & the mount out of sight real quick-like.
4. Also, wire in a flat/round (not curleycue) power cord into the electrical system. This is not too hard, as you can strip the positive side of a flat power cord and find a suitable circuit/fuse in the fusebox and then stuff the blade-type fuse in with the bare positive side power cord on the exposed upstream side of the fuse. You might also want to install an inline fuse from Radio Shack on the positive side of the power cord. Ground the other power cord wire on a screw that touches the frame/body metal. Remove some interior peices & route the power cord behind them.
[Note for 3 & 4: IOW, keep it from being the reason you get a ticket rather than a warning.]
5. Never be the fastest auto on the road or the "leader of the pack." Drive along "with hte flow of traffic" until some speedy fellow zooms on by. Let him get ~1/4 mile ahead or just less then one terrain feature ahead, whichever is less. Keep eyes on him and use him as your scout. Best case, Mr. Speedy also has a radar detector. Either way, when he hits hit brakes, you slow down to speed limit or thereabouts.
This system also works well in the dark, my preferred safe speedy driving time. I prefer to minimize the ability of the aerial traffic revanue collectors to muck with me, using the V=D/T method, which does not radiate RF or IR signal.
Good luck to all you SAFE speedy drivers. I hope to join you all in a few years when my daily driver is something more rewarding to drive than a Nissan pickup.