How good are they is a query that manufacturers will always try to avoid giving specific answers. Why? Devices are built with different mechanical and electronic parts that deliver constants and lapses affecting the performance of the device.
This is not just true to Brother Inkjet printers and even if loaded with the original Brother inkjet cartridges. Straight from the factory, these printers will work religiously and no amount of negative glitches will ruin a printing run. So, manufacturers will always insist that their product (printer) is really that good.
However, once the product leave the confines of an ideal environment, heat, moisture, wear and tear and dust starts to creep in and in time can affect the performance of the product. For the technically inclined users, this performance relapse is understandable and is no cause for alarm. But for the regular users any misstep is tied to the quality of the product.
Any printer that is placed on a closed space and ventilation is nil will always encounter problems in performance. Or any device for that matter left exposed to the elements, sun, moisture and others suffers because mechanical and electronic parts are susceptible to extremes. Through it all the rubber or silicone rollers are as well part of any malfunction.
So, are Brother inkjet printers really that good, of course but with bated breath because of the extremes that the product go through in its lifetime. That is why, after sales services are offered in anticipation of the malfunction that comes after the product has been sold. Otherwise, if the product is so perfect, after sales services would no longer be needed.
Are Brother inkjet printers that good, yes but up to a certain period of time, and dependent on the longevity of the device. Of course, never discount that the OEM Brother ink cartridge is an integral part when print quality is aspired.