You are not. A properly design system with ball-screws and servo should cut much better than one withe steppers and belt. But a poorly designed/assembled/inspected system with these components may perform worse than average stepper-belt system. The best way to approach this is to request samples made from the same file and material and compare them yourself. Additionally you may ask them for pictures of the internals to get a sense of the build quality.
Another brand you may want to check is HSG - Acrylic And Wood Laser Cutting Machine HS-T1313Z-Foshan Beyond Laser Technology Co., Ltd.
Ordering from China is never fun