I've tried many DSP preamps. The DEQX was one of the best sounding but most complex to set up. I sent it back. Others are much simpler to operate.
Still, a good result with DSP is never free. It takes energy and time get great results. The same is true of a lot of audio, whether it's speaker positioning, integrating subs optimally, or even choosing the right components for your taste.
I would not recommend DSP to anyone who can't put in the reading, and the trial and error. They would not be happy with it. The simplest thing is just to use some headphones -- you don't have to consider the room at all, and you don't have to learn anything new.