My K100C was bright stock and mellowed some with speaker break in. It got better again with a V30 but was still ultimately a bright amp which probably felt especially so considering it lacked a load of bottom end. I've owned a couple of Vox's and Marshall amps and whilst I generally head towards warmer tones, I do like some presence in my sound and like cut (rather than spike). The Katana head through a big, dark cab is absolutely fine IME. Through the stock internal speaker it's also fine and not bright like the combo. I use V30 speakers exclusively as they work for all musical styles from great cleans to detuned high gain. This speaker seems to work well with the Katana. If you're running a Jensen or a classic Fender speaker it's likely going to take your head off with a Tele. I remember a guy running my AC30 with a razor sharp Tele and my goodness did it hurt. He seemed happy but I'd rolled off the cut to nearly nothing and turned the treble WAY down by that stage just so my hearing would survive. One man's pain is another man's hearing damage I guess.