I've always lived by the believe that Cliff is smarter at me and knows good guitar tone better than me; as such, I follow his lead as what "progress" is with regards to this magical black box he created and don't feel I've ever once been led astray.
Lets put it this way, even on my most OCD day about tone/gear I'm not even at 1% of how Cliff is each and everyday. No one in this industry is as laser focused on continuous improvement of amp modeling as he is, and he simply isn't going to put out a bad (with regards to poor sounding) firmware. The man knows good guitar tone and I trust in him 100%.
I can certainly like what I like, but I don't have great ears, I don't understand 5% of the technical amp design stuff, and I'm not even that great of guitar player. Luckily, I've got Mr. Chase in my corner, working tirelessly on these improvements that I get to reap the benefits of. Can't get over how awesome that is.
The same guy that is working on improving the rigs of (Insert A list artist of your choice here) is giving me that same firmware, personally responding to my questions, and doing all this for FREE!
Buy another modeler and you get the same old firmware that its had since 2011, and you want tech support, you wait on hold 45 minutes and talk to someone who isn't a guitar player or an engineer and who basically re-reads the manual to you...
Have a question with Fractal, or a suggest ? The head of the company will respond, and many times, actually put that feature into the box. Think Line6, just as an example, would ever in a million years create a new firmware update with something that I PERSONALLY requested ? No way, but with Fractal, that actually is the reality.
James Hetfield, JS, etc and a nobody like me get the same rock star treatment from Fractal.....beyond words cool
So do I ever doubt Cliff or not update ? Never