Pros: design, build quality, warm sound
Cons: not for all genres
First of all, I have to admit it's design and build quality - it's really great, amp looking very stylish.
As for sound, I have to mention, that it's really giving "warmth" to sound. This is hardly explainable by words, but old rock, for example, starts sounding much more pleasant. I've listened Led Zeppelin, Doors, The Who and really rediscovered some of my favorite tracks in a new way.
Also I found it sounding good with almost all genres of metal, except Nu-metal. Very nice sounding for Nile, Behemoth and other "brutals"
Only exception I need to mention - it's dance music. This it amp IMHO is not for it.
To summarize - this amp is perfect pass to tube world with affordable price of $90