Subwoofers with room correction built in?


Who has experience, good or bad or whatever, with the built-in room correction/DSP/EQ that newer subwoofers (except REL) come with these days?  I’m excited to try the system built into an ELAC sub 3070 that’s coming my way soon, but I want to be realistic.
Thanks.
redwoodaudio
Given the trouble audiophiles have in correctly integrating a room, I highly recommend this approach in general.

The one thing to keep in mind is that auto setting software is not all the same. I really like the way JL audio's built in software sets their subs, but they are super pricey. You definitely should listen before buying if you can, otherwise it's worth keeping an open mind and being prepared to tweak.

A gently descending curve from 20Hz to 80 Hz to my mind sounds much better than flat.
@oldhvymech - my DIY skills are pretty limited so far, but I'm sure this would be a worthwhile approach.

@erik_squires thanks. I know JL is the real deal, but I have high hopes for the elac due to Andrew Jones involvement. 
I am hopeful you can make most self-adjusting subs work.

The parts they seem to do well is room integration and main speaker integration.  The part that is sometimes in question is the bass ends up too dry, which can be fixed by gently boosting the lowest Hz, 16 to 25 Hz and letting it slope downwards about 1 to 2 db/octave until it reaches the main speaker crossover frequency.
For less than $1k you can get the DSPeaker Anti-Mode 2.0 unit with built-in room correction and DSP equalization modes. Other units are out there but I'm not that familiar. These units can be used with your main speakers, in addition to your subwoofers, to take out certain problem frequencies. Some will go to their graves fighting DSP tooth and nail but I would not remove mine. The improvement to the sound of a good system is night and day, no kidding.
+1 @musicaddict Though I tend to buy from miniDSP.  Also, DSP works MUCH better if you have good room management.