I don't have experience specifically with the Ruger Hi-Viz sights. However, I did add a Tactical Solutions Hi-Viz fiber optic front sight to my Ruger Mark II 5.5" barrel and I love it. I retained the factory rear. It is a user preference thing, but some folks find just a hi-viz front sight plenty for fast sight acquisition. Some people find fiber or tritium rear sights a little more distracting. After all, you should focus on the front sight.
I added the same front sight to my TacSol Pac-Lite upper on my Ruger 22/45. Obviously these sights work great for me. ;-) And they are in the $20 to $25 price range IIRC. They are offered in green, amber and red. I went with green as most people (me included) see in the green spectrum a little better and the green sight doesn't wash out when I use it in bright daylight.
The downside to a fiber sight is that it doesn't have strong illumination in really low-light environments. They amplify available light. Too much past dusk and they won't be too bright. So, if you want better low-light you might look to get something with tritium.
Another option (though much more costly) would be to add a Picatinny rail to the upper in front of the rear sight. TacSol makes these for the PacLite and the same rail can be added to the factory Ruger upper; just need to drill the upper for it. But then this allows use of a small dot optic like a Burris FastFire. Just a thought and other option.
Hope this helps some.
Take care,
Mark
