Planned to upgrade to DeVore Gibbon X, but concerned about comment of base leanness

I would agree with @prof that the X isn't bass shy at all - in fact, too much on certain cuts in my 14x18' room. The Super Nine would probably be ideal but wasn't released yet. The Xs need space.

I have a set of the Devore Gibbon X in a 19 x 20 x 9 foot room and have no issues with the bass control in the room. If anything I will say that a lot of people don't realize how much of an affect an amplifier can have in this regard. I went from a smaller CJ stereo amp to a set of Merrill monos and the difference in bass weight and control was huge, almost startling.

Late to this thread. I've owned a pair of Xs since early 2019, paired with a Bel Canto Black Ex integrated, and haven't had any issues with the bass. If anything, the bass is a strong point ... well-controlled, firm, dare I say supple? I have a 14 (deep) by 25 (wide) room with the speakers along a long wall. Obviously room size, amplifier and positioning also make a difference. 

I have owned the Gibbon X for over 1 year. I had a total absence between 100 and 300 hz. and too many high frequencies (and I love the mid high and the high frequencies). Unfortunately I had ti sell them

Any high resolution speakers, when poorly set up in a given room or paired with the wrong amplification, can produce incomplete or undesirable results. The higher the resolution of the speakers, the more care that needs to be taken with set up and amp matching. The Gibbon X's are high resolution speakers. You hear what is fed to them.

I've owned mine for about 4 years. When I first got them, I had a 25' x 17' room. I moved house and now I have a listening room half that size (about 15 feet x 16 feet). With a bit of care and experimentation, I have been able to get the X's working as well in this much smaller room as they did in the previous larger room. And I have also listened to a number of other speakers in both rooms.

The X's are not at all bass light or bright when properly set up. The bass is powerful, deep and extended (more extended than the O96's for example). It's in the upper bass (100Hz - 150Hz) where many smaller speakers have a slight hump that the X's can seem ever so slightly lean, but you only notice that in direct comparisons. And when you put on a high quality recording with true low bass and hear the X's bass extension, that thought is gone! And what you notice next is how clean and detailed the midrange is. How boxless the overall sound is. The cohesion between the mid unit and the tweeter is remarkable.

All this assumes sensible set up, decent quality sources, good equipment isolation and appropriate amplification. I've achieved great results with an ARC REF 75SE. And btw, the X's are no fussier than most other equivalent speakers when it comes to set up.