QC slated to arrive today. Meanwhile, here’s a rundown of my own obsessive amp modeller experiences 
I started out with a Line6 Helix. Now, I know I’m in the minority here but, I didn’t get on with it. Easy to drive sure but the amp sounds were uniformly just a bit flat and lifeless to me. I found to get anywhere near a good sparkling clean tone, I’d have to run two amps in parallel and then a treble boost with low gain up front. Even then there was a soft/mushy/distant feel to the sound. If I were to guess, I’d say the modeller didn’t really create enough upper harmonics or intermod distortion but, like I say, that’s just a guess.
In the end I sold that and went big on a Kemper Powerhead. I still have a LOT of love for that product. Sure, it had a ‘signature sound’ the pervaded pretty much all the tones it made but, critically, I liked that tone. It was ‘fast’ punchy and did great cleans. Of course, the issues with the user interface are well known and most significantly, it’s a profiler. So, you can’t get too far from the original profile tone before it starts to sound a bit ‘off’ .This got better with liquid profiling but I still spent too much time searching for ‘starter’ profiles for a given tone and not enough time playing.
Next, I took a knee jerk reaction and went for a Boss GT1000. I LOVED this unit. It’s easy to use, built like a tank and the limited amp models meant less options paralysis. More importantly though, to my ear it sounded and ‘felt’ good, WAY better than the Line6 but with most of the advantages of being a modeller rather than a profiler. Used it for months and had a lot of fun. Probably should have kept it but, again on the clean tones, felt I maybe wanted just a bit more realisim.
At this point I nearly bought a QC and then took a hard left and picked up my FM9. Initial reaction was ‘wow, this is great’ but I soon found that I didn’t get on with the mid gain ‘crunch’ tones it produced. The fizz/crackle just seem too pronounced or, somehow, that it is not sufficiently ‘associated’ with the harmonic content. It’s a Fractal though so you can tweak to your heart’s content. About 50% of the models on there can be made to sound ‘as I want them’ but the time investment is huge. As I 've mentioned above, I could get a tone I liked in moments on all the Neural plugins. Not to bash the FM9 though, there are a couple of models in there that are stellar. The bassman is incredible for example. It’s just that you need to do quite a bit of work to get them to ‘sound right’. Naturally, YMMV.
So, I learned something, but probably should have gone straight to the QC. Clearly, I am a fussy sod but the Neural plugins do seem to work for me so I’m hopeful. I also love that the QC can do modelling and captures. I’ll report back.
I must acknowledge though that I seem ot have weird taste in this stuff. Of all the previous gear I’ve owned, it’s the humble Boss GT1000 that I could see myself buyng again and I know it is rarely on the top of anyone elses list.
Ta for all the posts from other users here. The key themes of decent tones and easy usability seem to confirm my experience with the plugins so I feel much more comfortable making the purchase. Cheers everyone.