Planning a build within a system with random elements requires meta knowledge, however same can be said about hand-placed uniques since you don't know where and when you encounter one until you play through the game and see. The only difference I see for the former is that you can't pinpoint the exact moment when your build comes together, while with the latter you can. In this regard I find the 'build your character journey' more interesting with the random loot system, at least in the long run, for consequent playthroughs. If anything lies in place then replayability suffers. And I tend to replay Larian's games a lot. As long as the drops are plentiful or the chances can be influenced - this random system should not be much of an issue, I think.
