I've used digital room correction for years, first as a plug-in to Foobar2000, and now with Minidsp's Dirac Live box. I rent and am a fixed-income. The former means I deal with rooms that are sub-optimal, acoustically. The latter restricts how much I can spend. The Dirac Live box corrects both frequency and time domains, and for my application, it's well worth it.
The weakest link in most stereos I've heard has been the room. I'd do room correction before I upgraded anything else, but budgets and rooms vary, so YMMV.