Let me start by saying I'm sure it is - I have, use and love both RMX and Omnisphere and am a big, big fan of how they sound, their user-friendliness, and the way Spectrasonics takes care of its customers (upgrades, tutorials, etc).
So the question is just this: I don't really use synth bass sounds for the kind of work I do, and while no one's going to hire me for that Bootsy Collins tribute band, I can play enough electric bass to suit most situations I get myself into while recording (I'm a guitar player). Which leaves the upright sounds. I love me some upright, and I know I would use it all the time, and yes, I'd be replacing, er, the upright from the Garritan JABB sounds (which actually, with some tweaking, sounds just fine in a mix of otherwise live roots-music sounds - I'm not exactly creating mockups of Mingus solos over here, either).
So the question is just - I'm sure I'll love the upright part of Trilian, but is it dumb to lay my hands on this one if I know ahead of time I'm going to leave 2/3 of it lying around 95% of the time? Yeah, I know, only I can decide that, but I'm just wondering if anyone else has had this dilemma.