Guitar Rig 4 Player is the free version of Guitar Rig 4, the program much less amps (one), much less effect, but much less so.
The best thing is to see the site to see native instruments amps / effects arranged. https://www.native-instruments.com/ # / en/products/producer/guitar-rig-4-player /? page = 1503
Installation without problem (I have a PC with Windows banal 7), such a configuration, if one is accustomed to this kind of software.
The manual, I flew, it looks clear.
As stated above, I use it on a PC banal, windows 7, with a Line 6 Toneport GX as an interface / sound card.
I expected to have latency, bugs in sound ... But nothing, so it's a good point.
One small bug: I like to play over the music, but this is not possible too: when I launch the player and I play at the same time it makes me to "click" all the time ... but my pc is probably not good enough.
I use it since its release, I am satisfied for now.
Before I used Gearbox or Podfarm I downloaded Guitar Rig for a change of sound, and especially to use Rammfire because you can use with any NI products.
The pros: Easy to install, Free, the main effects are arranged (lack may be a phaser)