We have a UM2 in our workshop and love it. We getting reliable prints (with a few mods) in PLA, ABS, NYLON from ultra small to prints the size of the bed.
Although the one problem we have is we would like to upgrade to a dual nozzle, for multiple reasons:
To be able to print supports in a different material
Also when our UM2 nozzle blocks it cost ~£30 for a new one (last on lasted 1 print which we think was a blue moon occasion [one off] )
An all metal hot end would allow us to print higher temp materials with maybe more mods to the power supply etc
It looks like there are one