I know it's strange for someone to give an opinion that holds different extremes at the same time. Alas, that's where I find myself with lots of things in life. I think the randomness could be fun if they buffed drops of them, while also thinking a more deterministic way to get them would also...
It might be the best use of a legendary part, or maybe not, but regardless it's annoying and tedious. I just don't care to lvl anything to lvl 6 because I don't care to take part in the system. There needs to be a more deterministic way to do it if they do it that way.. or, as others have said...