Got a trial for Serpstat and tried the clustering tool. Tbh, it looks not bad. Keyword cupids reports are more simple. The Serpstat cluster report comes with more information, maybe you can call it messy.
Was not able to fully test keyword cupid. But groups keywords into big or small silos. In the big silo you can see "page theme" which is the main keyword i guess, and the supporting keywords for that main keyword. If there are similar main keyword" they will be grouped together. For example, I had "classic roulette" and "roulette red or black" grouped together and then you can see the supporting keyword for each of them.
For serpstat, you can see keywords, then the group name, then the cluster name. For example, 1 group was "keno tips", then there are a "cluster name" called "best keno patterns", with 4 different keywords in that cluster. So "best keno patterns" is the main keyword, and the remaining 3 is support keywords. Then there's another cluster name called "how to win at keno" with 5 different keywords in it including the main. So I'm thinking if "keno tips" could be pillar page or main page/category" then the "cluster name" are the pages under the main page. And that becomes the silo.
Could not import as many keywords for keyword cupid in the trial. Was able to use more keyword in the trial for serpstat, so I was able to see more with serpstat in this test. Want to try keyword cupid with as many keywords to see how the report will be.
But pros and cons so far for both. Keyword cupid have higher keyword cluster "credit" and you can import files from Ahrefs, semrush etc. But the tool is ONLY for clustering keywords.
Serpstat has many different tools compared to keyword cupid. But for the same price, you get a lot lower clustering "credit". for 149$ you get 6k clustering credit vs cupids 20k credit. But then again, you get more features and tools from serpstat.
So far, I quite like Serpstat's report and how they cluster. But the price is a bit high since I'm only gonna use the clustering tool. Contacted them to see if I can get a custom subscription more focused on the clustering tool and get a higher credit and possibly lower price if I'm not gonna use the other tools/features. Might also try keyword cupid for 1 month and try it out fully.
Wish Ahrefs could add a clustering tool like this, would be dope (and saves money and fewer tools to think about

). Or actually maybe not, then everybody is gonna use clustering.