Line 6 Updater actually works really well
I just updated firmware on a guitar amp for the first time ever, and it actually went very well.
The guitar amp I own is a Line 6 Spider V 60. Line 6 as a company is pretty good about releasing firmware updates for both their software and electronics products, so I decided to go ahead and download the Line 6 Updater from their software page and give it a go.
Before I get into that, I am ordinarily the type of person who sincerely believes in, "If it ain't broke, don't fix it." This means if for anything electronic, if it for whatever it is (phone, computer, software, etc.) works just fine, don't screw with it.
This is a little different however in that when you update a Line 6 Spider amp, you sometimes get added features you didn't have before. For the v1.05 update on the Spider V 60 amp, the factory patches have been improved, and you get a new "Phones Mode" global setting that now allows the headphones jack to act either for headphones or a stereo line out. This in effect gives the Spider V 60 amp a new way to output direct-to-mixer whereas it didn't have this feature before, totally for free...
...so I said okay, let's do this.
I downloaded the Line 6 Updater software and ran the firmware update. It took about 2 minutes for everything to complete, but it did work on the first try with no screw-ups.
I can now say confidently that yes, Line 6 Updater actually does what it's supposed to do and actually works.
Color me surprised.
How it's done
Line 6 did make this really easy.
Connect the amp via USB to your computer. No software drivers should be needed. However, if you do need the drivers, you can get those and install first from the Line 6 software page linked above.
Run the Updater installer.
You will be prompted at some point to create a Line 6 account. This is free, and optional. I went ahead and did it.
Look for the latest update to your Spider amp and click on that.
The software will tell you what firmware you have installed on the amp right now. If it's a number lower than the latest version, then install the latest version.
That's basically it. Just let the software do its thing and leave the amp on and running until all is completed.