I’ve had it for about seven years. For my MM carts, I am perfectly happy. I use a solid-state preamp with adjustable settings for my MC cart. Describe the sound…hm. Essentially, all I really wanted was something a little more tubey and less solid-state, but decidedly neutral. I wasn’t looking for warm and flannel '50s fuzz (BUT, and I stress, you CAN do that if you slap in some 1960 Mullard tubes or 1950’s RCA black plates). When I played around with various makes of tubes, I was looking for all-arounders that played nicely with rock, jazz, classical, hip-hop, etc., and both male and female vocals. So I suppose I would describe the sound as “get-out-of-the-way-of-the-music”. Although anyone with golden ears that I have given recordings to has been able to tell my solid-state preamps from the tube one. The only thing about the Cornet3 is the acrylic case can be sensitive to interference compared to some of the metal-encased amps based on placement, but this is never an issue listening with speakers, just recordings made with it and listened to loudly on resolving headphones.
I found Hagerman when I sold my old 80’s receiver for a 5.1 model in the early 00s (sorry I did) and needed a phono preamp. I think I was on the Steve Hoffman forums and somebody mentioned his under $100 Bugle preamp was bang-for-the-buck great. As my setup got better, I just moved up on his food chain.