I (185 lbs.)have ridden three sets of wheels over the last few years that I have put enough miles on to form an opinion. These are…
Spinergy Rev-X: This wheel “feels” the slowest of the bunch, but I think this is due to the fact that it is MUCH heavier than the other two, which means that acceleration is much worse. Other than that I was always happy with my Rev-Xs, and dispite all of the catastrophic failure reports I have read, mine have been bombproof.
Rolf Prima Vigor: The Vigor “feels” much faster than the Rev-X, but once again that is probably due mostly to the weight difference and thus the better acceleration. I also feel the bearings are much smoother than the Rev-X. I rode my Vigors last year almost exclusively, for both training and racing, and they held up quite well. Now they are my primary training wheelset, and my full-time road bike wheelset. I have never had to have them trued, but I did have a failure of the back wheel in Aug. of this year at ~2 years and ~5,000 miles. I went around a corner, stood on the pedals, accelerated, and ripped the spoke out of the hub flange. It wasn’t the spoke head that broke, but the hub flange itself. The wheel went back to Rolf Prima where they replaced the hub and the spokes free of charge despite the fact that the wheel was already 1 year out of warranty. Suffice it to say that I was very happy with the way they stood behind their product.
Zipp 606 (tubular): I have only had these wheels since May. They are mainly my race wheelset on my Tri-bike, but I also rode them on my road bike a few times while the Vigors were being fixed. As luck has it, the day after the Vigors were back from repair, I found a crack in my rear 606. Needless to say Zipp fixed it quickly under warranty, so no problem with their customer support. Regarding performance I would rank the Zipps a little better than the Vigors, however once again I suspect this is due to the lower rotating mass and probably slightly smoother bearings.
In summary, based purely off “feel” I would say the Zipp 606 edges the Rolf Prima Vigor by a small margin, with the gap to the Spinergy Rev-X being much larger. To really understand which wheel performs best you would need to do repeats in a controlled environment and measure the average watts required to maintain the same speed. I don’t have a power meter so I am stuck with drawing on the riding sensations from miles and miles on the road.
Having said all of that I would say that the Rolf Prima Vigor is a good wheelset, that is reasonably light, and reasonably strong, and Rolf Prima stand behind their product. It can certainly be used for both training and racing. While there are other wheelsets out there that may perform better, you will probably be paying a large sum more money for only marginally better performance (typical principle of dimishing returns).
The only other thing I would point out to you is to take consideration for your typical riding environment. If most of your rides are fairly flat you may want to consider something more aero but heavier, like the HED Alps or Stinger 5.0, or Mavic Cosmic Carbone. If you do a lot of climbing the Vigor, while not a pure climbing wheelset is probably the better compromise (although the Stinger probably climbs as well as the Vigor, but I am only speculating).
HTH