Hi aeolian, welcome to our hangout!
I know what you are talking about. I bought my amp with the intention of using line out for recording. My take is - forget it. The line out bypasses the valve circuit in the amp, and the sound you get when recording is mediocre, in my humble opinion. I would think the J-station sounds better for this purpose.
I have tried miking the amp though, and WOW! - you can get killer sounds!
In summary, a Vox ADxxVT for recording purposes - not recommended by me.