A lot depends on if they will reproduce or not. In my younger days when I did a lot of bucket stocking, I stocked them in 8 different ponds. Of the 8 ponds, they only reproduced in 2. Those were larger ponds with gravel bars where streams fed them. I believe this is where they spawned. In smaller ponds, they aren't able to find spawning sites and therefore they didn't successfully spawn. In ponds where they were able to reproduce, they stunted badly. 5-6" fish were the norm with a big one going 8". I am sure they directly competed with the bass, sunfish and others for food. In the ponds where reproduction wasn't successful, they had little competition with each other and I was able to grow some over 16".
Remember, white perch are closely related to striped bass and are similar in many ways. In their native habitat they are coastal river fish. In the spring they migrate up rivers to the area of the fall line where they spawn on rocky gravel bars with a light current. After spawning, the larger adults migrate down river and hang out in the brackish bays and sometimes even full blown ocean areas. The small fish generally stay in the middle to upper reaches of the river. Come fall the fish start making their way back up river holding in the deeper areas of the middle to upper river before they make their spring spawning runs again.
I agree with Bruce, they have a good fight for their size(much like white bass and HSB) and a good taste. Deciding if you want to stock them is a weighing of the risks. If they do find a way to reproduce, they will be a challenge to manage. They have a very high reproductive rate. If you live on the east coast in an Atlantic drainage where they are native, stocking them would be less concerning. However, if you live in the Midwest where they are not native, I wouldn't stock them as this can lead to them spreading to other areas where they aren't native.
Here in the east, they are found in most reservoirs near the coast. When those reservoirs were dammed, the white perch were trapped and took hold. Much like stripers initially were found to be suitable reservoir fish when they were trapped in Lake Moultrie. In these reservoirs, they tend to average 6-8". Where as the river perch tend to average 8-10". The difference being the much richer food environment large estuaries are. So even under ideal conditions in a pond, you're going to struggle to grow fish bigger than 8".
Breaking it down, in the ponds where they didn't reproduce they were a fun bonus fish. Stocking them runs the risk of them reproducing and making a mess. Weigh the risks and decide... However, in a private pond that I spent $1000's if dollar to build and stock, the risk probably outweighs the benefits.
