wheel bearing problem???
 

At highway speeds, my car has an intermittent vibration that is most noticeable through the steering wheel. The vibration isn't too bad going uphill, can be bad traveling along flats, and is at its wost going downhill, but it does not happen all the time. The vibration can get so bad that my hand holding the wheel gets blurry. Under 55mph, the vibration does not seem noticeable; it seems to peak in the 70ish range. I don't think this is an alignment issue because the car tracks straight, and the vibration happens with both my all-season wheels/tires and my AX r-comp set. (It's much more dramatic with the r-comps, but then again those tires give much more road feedback.) A couple of times I've stopped at a rest area and felt the wheels for temperature - the fronts are warmer than the rears, but not hot to touch. The car has 120,000 miles, and K-sport coilovers have replaced the stock struts.

Any thoughts or similar experiences??

Sounds like a balance issue to me. To confirm, get your car in the air, spin each wheel and listen. A bad bearing will sound like there is sand in it. When I had a bad beaaring there was a very noticeable grating howl while driving. While the wheel is spinning, observe varaitions in tire radius - no balancing machine will perfectly balance lumpy tires. Grab each wheel at the 6 and 12, as well as 3 and 9 o'clock positions and try to rock them. Identify source of any play. If this all checks out I'm just about positive you have a balance issue. Google up "Hunter Road-force" to see if one of these machines is in your area. It's your best bet for solving balance issues. Sorry if this was too obvious.