I've owned a Blackmore with V60 slant cab for 2 years, then I chanced upon a second hand Herbert, and after getting that I sold the ENGL to my bandmate (couldn't justify having that much firepower sitting at the house)
I think a lot of people underestimate the Blackmore, thinking they have to get a powerball to get metal tone. I think the Blackmore sounds the best out of all ENGL's (have not tried the Invader though) for my specific kind of chuggable tone  
 
 
The fireball is a very good second but is a lot more compressed, and has some breathing troubles at only 60 Watts. (the 100W version should be interesting though!) The Blackmore sounds just awesome with a band.
I ran the Blackmore with V30's but that is too much mids for metal to my liking, but it sounds just awesome with the V60 cab.
Some people say they have poor build quality but I have not had a single problem with it, stood up to loud gigs and loud rehearsals, and a good bit of hauling as well.
My settings were bass/treble at noon, mids at nine, a bit of presence, lead at 8 or 9 (depending on pickups) master set to taste.
They are IMHO absolutely the best bang for the buck tone outside of the "boutique" builders (Diezel, Bogner etc.)
I feel a sneakin' GAS coming on  
 
  
 
- Rune