Ok, so had an hour or so of playing around with the full instrument, not the demo. Now, I am definitely not a guitar player, I do own a decent Yamaha acoustic guitar and also a nice Ibanez Strat copy which I can kinda play, so I have a fairly good idea of what a good instrument *should* sound like.
RealRick comes with stereo and mono 6 strings and an 'A' and 'B' twelve string. As far as I can see the difference here is that the strings are detuned a bit more for one of these sample sets. As with all the other instruments in the series, you have pretty much the same levels of control including the ability to move the pick position which, as I said, does provide a very substantial control over the tone and can be done in real time.
The sound is, as you'd expect, jangly, but, to my ears at least, beautifully sampled and you can certainly play along to the Byrds and sound pretty darn close, depending on your chops. Of course, as with all these instruments (RealGuitar excepted) you really need to plug in an effects stack or the raw sound will be a little underwhelming but that's exactly how it is for a real electric guitar.
You can actually get quite a good jangly sound from the Les Paul but it is quite a bit more full-bodied, the Rick is a thinner toned instrument which takes up less of the mix. The very top notes have a fairly short sustain - or more accurately, drop back fairly quickly in volume - there's no suggestion that the samples are truncated in any way. However, not owning a real instrument I assume this is probably how it is. I can hear no evidence of aliasing or any other digital artifacts on the top notes.
Plugged into any of Guitar Rig's more extreme solo lead patches, there is plenty of sustain at the top end (obviously, there's usually a compresser in the stack for these patches). Overdriven, the Rick gives a very clean lead whereas the Les Paul is, again, rather crunchier and thicker and of course the Strat has that characteristic enharmonic attack that outlines every note, almost like a chime is the best way I can describe it. You really notice that in the Strat's lower notes, which is what makes the other two guitars somewhat better for those powerful solid low lines.
I also like the Rick for rhythm; you can play staccato chords and get something that, again, doesn't take over the mix but has clarity and punch.
As with all the Real series instruments intelligence is used so that if you play two notes successively that on a guitar would usually result in a hammer on, for instance, then by default that will automatically be applied. Of all the plugins I own, the Real guitar series really are 'musical instruments' - you can set up to 5 different samples per note to play so notes never sound mechanical, and the sample sets load very quickly.
I just looked at MusicLab's site and all four plugins will set you back 549 bucks. Now that ain't cheap, I admit, but, if I had to start all over again I'd still be buying the full set. Every guitar has its own distinct character and lends itself to different styles. I also like their simple licensing scheme; you get a license file which is not keyed to your individual computer which makes it easy to move software when you upgrade, for instance. You do not need to re-register online.