The VNA dataset has three features: frequency, S21, and phase, while the MIMO dataset has an additional 'Channel' feature. The VNA dataset is larger than the MIMO dataset, with 507,709 rows compared to 164,161 rows in the MIMO dataset. This is because the VNA dataset was sampled at a 1 MHz resolution, while the MIMO dataset was sampled at a 25 MHz resolution, which is the limit set by the MATLAB API. As a result, the VNA dataset provides 4,701 samples per tag, while the MIMO dataset provides 190 samples per tag per channel for each reading.