I just purchased the VHP-2 and matching VAC-1 to go with Senheiser HD650's. I am relatively new to getting back into headphones, so I may not be the best one to listen to on this. I like that the amps are small, good looking, offer gain selection (high or low) and have a monitor pass through if you need it. I run them off of my record outs on my TEAD Vibe and so far everything sounds great. I also like not having to mess with tubes. You should look at the Wes Phillips Stereophile review. Interesting how he likes the sound of the CI at least as well as (although implies better than) the MF X-Can with his 650's but the X-Can gets Class A and the CI gets B. Draw your own conclusion.