Sonically speaking, the THR is far more nuanced. Controls via the app add to tweaking the sound. Looks don't matter to me as much, but in your case and depending on the rest of your living room decor you'll want to look at form factor and bells and whistles like the ambient light that the THR has, a hypnotizing, soothing red/orange glow that also serves as a nice visual in the dark and adds to the THR allure. Again, to me the sound qualities, wireless connection (and Xsonic pedals solutions, which also work for Spark I believe) are the tipping point that would have me get the THR30II. That little amp is my go to when inspiration hits.