What percentage of audiophiles use a sub ?

Whether a Sub goes Boom Boom or it harmonizes and locks in with the room all depends on how you place it and dial it. I Have Rel Strata and it sings with the crossover set at 22 Hz !(I user merlin TSMs)the difference is not just in hearing the Foot stomps and deep bass in musing like Grandma's Hands (yup lot of sub 25 content there), but also in cds like Clapton unplugged.
cannot live without a sub ( or a full ranger at 3X the cost) now

Thomas Trouble
Sub-woofers are fraught with problems in a High end system as so many attempt to use just one
and don't like it.
These problems can be minimized from the get go by making sure the sub has some mandatory features.
1st the most important is that a high pass must be used in order to maintain a linear transition is at least possible between the sub and main speakers.
This will also lower distortion dramatically in what now will be a mid bass driver in the main speaker
and IM distortion in the main amplifier.
2nd A sub that is not forward firing to eliminate the nonlinear spurious radiation from the surround and cones
that interfere with mid range information and blur imaging.
3rd a Sub with a quality usually heavy enclosure that is sealed for optimum transient response.
4th If the system is to act as a larger system in a mid sized room Stereo Subs.
If all of the previous requirements are met and with careful placement a Sub can be a major improvement in most systems.
In large rooms there is no substitute for a full range loudspeaker as in the racing days there is no substitute for cubic inches
Cheers Johnnyr

Audiophile - subwoofer in the same sentence? Getting a sub means your speakers ain't good enough.

I am using a Genesis S4/8 sub and 7.1c monitors with Core audio diffusers
and bass control by a combination of diy, and a Guizu modular type product purchased through Grant Fidelity. I am still in the process of dialing evrything in, but the combination of my Genesis system and acoustic products gives me a lot of options in dealing with the acoustics of the room.
I took to heart the advice I have read here, about the speaker and room interaction being paramount. I would suggest considering that advice rather than a yes or no mind set.

I've found that subwoofers are difficult to balance with the rest of the system. Like others have said, the bass level varies on recordings enough that no one setting works well.

Another issue for me is that my receiver doesn't allow the use of a subwoofer in Direct Mode which is where critical listening is at its best. When the sub is active the receiver is actively processing the music. I love it for home theater and some "low rider" music demands loud bass.

When I was listening to my speakers at the store I took in some song with heavy bass to listen to and found out that the clarity of the sound was more than enough to forget about the lack of bass compared to my previous speakers.

I've heard the Focal Grande Utopia EM in combination with the JL Audio Gothom subwoofer and that's a pretty nice combination, but I'm not sure why the EM would ever need a subwoofer unless someone was just spending money to impress.