I have had the cubicons for 6 months and the only service issue was with a board in the print head that connects the exchangeable printer head to the carriage. The little pogo pins got stuck and wouldn’t detect properly. The local rep sent out a new board and it was easily changed out.
I had a upbox but it was too painful to use. The print quality was pretty much the same as the cubicons but it took twice as long to print the same item and failed more often than it printed. It was another closed ecosystem and locked down slicer which I am not a fan of.
It it is strange you don’t see too many comments about it, it is a great printer, there are a few more reviews of the cubicons style 3D printing nerd did a good review. Pretty much same goes for the single only with actively heated chamber I think.