2 five star ratings by users that are only here for less than a month ?!? - fishy :-).
The software itself is very good. Especially when you take the (current ?) price into account - zero/nothing/nada.
It is very easy to dial in a good sound and whoever needs a manual or instruction how to use it has never seen a amp sim before (or maybe not even a computer).
I have only played around with it for about an hour and so far I can't really say anything about stability but the rest looks like this:
- very easy to dial in sounds - good amount of good presets - easy on the CPU and very fast loading times - quite a few FX and amps to chose from - realistic sound.
- maybe not the most dynamic reaction to your playing - no 5150 sim (sorry, but that is one I always love to have) - not too many bass amps/cabs (1 each ???) - no way to set the amount of oversampling (and no info on that at all) -> all in all not really much that you could argue about in a free sim;-).
...after an hour of playing around with it it has replaced my goto practising sim (Audified ampLion (payed version)) and might even end up as my goto sim for composing because of the perfectly fast loading time (to be replaced than later in the process by a more sophisticated sim).
To sum it up: For a free sim this one is clearly at least a 4 (add the 5150 model and I have it at 4.5-5;-)).