Don't rely 100% on youtube demos. It compresses the audio too much. Not to mention the speakers/headphones you're using, will also affect it.
I'm with FM55, it has to be seen and heard. There are good SS out there, but I prefer tubes. A lot of SS/digital hybrid amps simulates how a tube behaves. Even all these Kempler, Axe FX etc-etc, they all copy what a good tube amp sounds.