I'm a huge two notes fan, le bass + torpedo CAB is absolutely killer and my go to set up now for live and recording. That said I owned a noble for a bit and that was the only preamp that made me question my two notes combo. It's difficult to do a straight comparison of the noble to le bass because they excel in different areas so your personal preference and application will determine which you may prefer. Basically though i think the noble sounds like a $900 pre amp/DI....it's that good. There's no noise whatsoever, the tone is so insanely warm and fat, I literally couldn't find a bad tone. I only sold it because I needed the cash at the time and I also want to buy one from Jack at noble and support a company like that. In a straight comparison I could hear the difference of the noble to le bass just comparing my favorite tone from each, it wasn't drastictic but the noble did seem cleaner with less noise, tighter, and it got spongier in a tubey way...I'm typically not a person that buys into more expensive gear= better but you could hear that it was a $900 pre vs a $300 pre. I don't know that a non bass player would detect the difference but anybody on talkbass would. None of that was really surprising to me, everyone loves the noble for a reason, it's fantastic.
Now for le bass, sure I thought the noble sounded better but that wouldn't surprise anyone it's a $600 difference it should sound better. But it wasn't drastically better, and don't get me wrong Le bass sounds great, it's a monster it just doesn't sound as refined as the noble. Where le bass earns my respect and a permanent spot on my pedal board is its versatility, it offers 4 different and equally fantastic tonal options. The dirtier tones on le bass are worth price of admission by themselves and the fat clean sound I think far out classes it's equally priced challengers.
Another big factor for me is going through the torpedo cab, as much as I like the noble I like it better through the CAB. When I compared the le bass through the CAB to the noble through the CAB the difference seemed even more subtle to me.
at the end of the day though I love my le bass and I'm excited to eventually add the noble to my board with it...in the meantime though I'm waiting on a Broughton audio 1073 inspired pre/DI that I should get this week that I can't wait for!