Before I'd scrap the stove and get another unknown preformer, I'd work on the stove. That's the old, "My used truck doesn't run well, but it gets me there and I know what's wrong with it, and when I get money ahead I'll fix it, but until then....." That's right, fix the known or suspected performance issues.
BUT, you "don't think it's performing well". There is the nitty-gritty issue. What do you expect from the stove and what is it doing? Are you expecting too much? Is the stove not performing, or are your issues with the fuel, the installation, the location, the area you expect to heat... and so forth. Now you need to jump in the hot seat and let the forum do your talking.
BTW, the Kozi is not the most popular stove on the forum, but my experience is that the issues I have seen are often traced to owner errors. Bought one a few years back for the price of scrap. Guy said it wouldn't heat for sh...
Fact was, he had run three tons of really bad pellets through it and never cleaned it. I have never seen a stove so choked. Current owner is heating twice the area, loves the stoves and gets her kids involved in the Saturday morning clean the stove party. Clean stove means pancakes
! Another was a broken hopper switch, too many bags slammed down on it without thinking... Was that the stove's fault????
Not trying to imply you don't pay attention, just that in neither case was the stove the problem.