Feature Availability: 3/10
While some features are nice, like the custom homepage, there are loads of missing essential features that make the life of an panel owner easier. Who wants to go through and add all 100-1000 services by hand?! That's ridiculous. The payment gateways (I assume it's more than one that uses sole-API implementation) should be better documented and integrated using their official payment gateways, and not just their API handles. This causes some issues for large panel orders.
Design Quality: 8/10
This is something that BrothersLab did very well on. The overall design of the script is clean, and easy to navigate. There are some minor issues on mobile, but those can be fixed and handled if you understand some basic HTML and CSS.
Documentation Quality: 5/10
This is a half-rated section because the essential documentation is there for getting the installation completed, but it lacks in quality documentation for the basics on starting up your panel after it's installed. I had to go and manually reset my admins password on install because the default credentials weren't documented.
Customer Support: 5/10
Another half-rated section. The customer support I've received has been medium-grade quality. Short responses, without much declaration on the issues at hand.
Code Quality: 5/10
I give this half-rating because the code quality is not that bad, but the features of the code should be better and more advanced. Especially for $89.
Overall, the product needs more features without you trying to upsell separate features that should be included in the original package itself (I assume that's why you ask everyone to contact you separately, rather than state that those features or requests are in the works).