Before purchasing the Captor, I had been using the emulated out feature of my Marshall DSL20CR for home recording. While the classic gain channel was passable, the ultra gain channel sounded horrendous and was basically unusable for home recording.
The Two Notes Captor completely opened up my amp and I could finally hear what it was capable of. The classic gain channel turned up full suddenly produced a beautiful crunch tone, and the ultra gain finally sounded like it was supposed to sound. I record with Reaper and the Two Notes plugin with the virtual cabinets give me a lot of flexibility.
Aside from this, it works excellently as an attenuator for home use and I can open up my amp without bothering the neighbours. Before buying the captor I was using a volume pot in the effects loop, and while this succeeded in lowering the volume while pushing the preamp, the power amp was not being pushed so I could not benefit from power amp distortion. I noticed a huge difference in tone, especially on the classic gain channel.
I will say that the built-in analogue IRs for guitar and bass aren't great, so if you are looking for something to plug directly into the mixing board for live performances, I would probably go for the Captor X to avail of the greater variety of built-in IRs, but for my needs this is a perfect product.