I would tend to agree, the Extreme Q is a great machine. I've never used a digi volc, but I have use the analog one, and I was unimpressed. I felt that they let too much air in with the vapor.
I've owned my extreme Q for about 2 months now, opting to replace a 2 year old and very noisy Vapir One. I probably did 2 month of research before buying the Q, over a volcano, based information I could find on the internet.
Really its going to break down to what you want. Do you only want to fill bags? Get a volcano and learn to use it better than I did. Do you only want to hit a whip? I'm told get a SSV for that, you can pull bong rip dense vapor outta them. If you wanna spend less 200 bucks, and get a vape that is an all arounder, get the extreme Q.
If you do get the extreme Q, I suggest using the "pack the elbow" method as well. It's hella conservatory and give more dense rips. If your asthmatic or have any lung problems start with the heat low and work up til your comfortable, but thats basic vape rules there.
Just my 2 cents
-Kr0n