I have had the chance to use/hear my Geddy Lee in a number of settings recently. Church, jazz gigs and now recording some really cheesy arrangements of standards. I have also been going strictly IEM (nothing fancy, just a Rolls box and Yamaha buds - but it sounds pretty darn good) and man is that nice.
Anyway, I have been pretty happy with how much I can do with my Geddy, some volume/tone knob tweaks and my right hand placement. Been sounding pretty good lately if I do say so myself. The best DI I've used lately has been the Radial JDI - and yes, there is a difference between it and say a "insert brand" basic $40 DI - especially with IEM's.
Because a majority of my playing is at church (IEM) these days, and all my tone is coming from my fingers, bass and DI, I have given thought to getting a really good DI - even more than getting a new Roscoe 5 string bass.
I know it sounds fine to everyone - even me - but even other guys I play with can tell when the DI is good, and I'm hearing better and playing better. I may be changing my mind on the "no one notices or cares" debate.
Still not sure about a DI that costs almost as much as my bass.