I just got my 89 3 months ago right before the 2.0 update. I played with the 1.9 version for about a month and thought the 89 was fantastic sounding I was really impressed. I mean WOW! Then I installed 2.0 and have had issues with 2.0 since installing it and it reboots my HD500. I have tested my 89 on 4 different HD500's (per L6) and they all reboot with 2.0. I even sent in my 89 to L6 and they replaced the battery compartment and sent it back stating it was fixed and it wasn't. I am not saying that 2.0 is broken but I think there are issues. Yes I told L6 this as well.
Just my opinion... From a new users stand point, 1.9 has a lot of character and feels good. Like I am connected with the guitar. With 2.0 it sounds thin, very little character and feels like I am unconnected when I am playing. It feel like there is a little more latency in 2.0 that makes me feel like I am not connected with the guitar. Remember just my opinion.
I rolled back to version 1.9 about 3 weeks ago and I am back in love with my guitar again.
Thanks to L6 for providing other firmware options because you can always go back to an earlier version.