So my question now is which is the better option of hardware that is reliable enough with less maintenance and problems.
Then that would be the Avalons. Over the past few years I've ran several dozen of them from A721's on up to the latest: Zero major problems and just 3 dead fans. Frankly I doubt any other makes is more reliable.
Only one I way say to avoid is their A921 series and that is just because the 841's can be made to be just as efficient in power/hash rate. It also uses a larger fan that can be rather hard to find a replacement for.