Guitar Pro 8 is not free, but it offers a 7-day free trial that includes all features, such as the Realistic Sound Engine (RSE)
It is relatively lightweight, though loading large soundbanks (several gigabytes) can take a moment on older machines. Customization: guitar pro 8 rse free
The RSE is the high-quality playback system that replaces generic MIDI sounds with realistic samples. 200+ Soundbanks Guitar Pro 8 is not free, but it