I've had multiple DSL50's, and I honestly never had any issues with performance, problems, etc. It's honestly one of my favorite amps ever. Needed good tubes, and proper bias.. TSL? Different story. Had a 60, and it was awful, as were the footswitches. Went through 2 and gave up, (bought one new, but it was messed up and the footswitch was defective. Got a replacement, and that one's footswitch broke after a couple days, and I hated the amp. Back then when I worked on many other people's amps, the TSL100 was always the most popular broken one. And, I honestly thought they sounded like shit. The DSL was so much more Marshall-esque, and the TSL a hot mess.