I've used both type of sights extensively for many years. Mostly using an OL-5000 and various Spot Hogg sights. The last year or two my eyes have really gone south and multiple pins just blur together. Of course, I've also made the mistake of using the wrong pin once in a while, although not while hunting. I used to strip the multi-pin sight down to only two pins for hunting.
This past year I've had to go to the OL-5000 exclusively. Less pin blur, although it's still there (Specialty Verifer needed now). The only thing I did have to do is wrap electrical tape around the housing to tone down the fiber some. It's too bright for my ailing eyes.
However, if your eyes are good then it can be a wonderful sight, especially for hunting. It's ruggedly built with a nice wide guard that protects the pin better than any other sight I've ever used. It's quiet and adjusts easily enough. If it has one drawback it would be it's mass weight, but that's part of the price to be paid for quality. The only thing that even remotely resembles plastic is the fiber and the nylon washers at the pivot points. The rest is all machined aluminum.
If you read the warranty information from HHA all their sights come with a No Questions Asked Lifetime Warranty.