We reported numerical results based on quantum vibronic wavepacket dynamics, which required the use of special sparse methods to handle the computational cost required for the full system (25 degrees of freedom) and for 200 fs of dynamics. Quantum-classical calculations are, on the other hand, more affordable from the computational point of view, even though the coupled-trajectory Tully surface hopping scheme derived from the exact factorization, i.e., CT-TSH, is more expensive than standard fewest-switches surface hopping, i.e., TSH-ED, which uses independent trajectories. While some differences have been observed between quantum and quantum-classical results, that require additional investigation -as for instance the effect of the environment on the electronic excited-state population, it seems that the agreement between CT-TSH and TSH-ED improves as the number of environment modes increases, suggesting that the environment washes out some quantum-mechanical features that might be present in the coupled-trajectory scheme.