I didn't say their game was timid, I was talking about personality. I can't imagine Efren or Bustamante being physically aggressive.

From my experience, the grip matches player's personalities, this isn't something carved in stone, just an observation. I really hope to reach players that are more aggressive and have them experiment with a firmer grip, it may be something that will help them enjoy the game more. As far as "firm" being something that locks up muscles, that's not dealing with reality. I'm trained in several martial arts weapons, especially with swords and staffs, you have to hold firm or they'll fly out of your hand and make shish kabobs out of innocent bystanders.
The greatest players I've met held the cue firm, this may be something of interest to players.....or not, who knows if you don't try?!?
The opposite of a firm grip is what? A loose grip seems to be the best answer. Firm versus loose seem to oppose
one another. The question was whether a firmer grip affected the feel and touch of the cue ball. Well, the only thing
allowed to touch the cue ball is the tip of your cue when you stroke it so touch of the cue ball translates into feel.
Okay, just gotta set the groundwork by going back to the original question. People are debating a loose grip vs. a
firm grip and that was never the question. It was always does a firm grip affect the tactile feeling in your fingers and
lower palm area where the cue butt is held. That is the very definition of feeling and the stroke velocity affects it too.
You derive a sensory feeling when you stroke the cue ball and how fast, i.e., hard, you hit the cue ball affects feeling.
Other things can also affect the feeling like was your stroke straight and true, where you struck the cue ball, did you
use stop, follow, draw, stun, center ball, or side spin English, the brand & type tip or how much leather remains, it the
tip shaped correctly or is it mushroomed, etc. As you can see, there are a variety of elements that can influence how a
player’s grip connects with the stroking of the cue ball. So when the tendons & muscles in your hand, wrist and forearm grip the cue butt firmly, the sensory connection becomes more immune to slight changes and deviations than when the
player uses a handshake grip without squeezing the cue butt. Grasp the butt with slight to less than medium pressure.
The best answer is to stick to the original question instead of meandering into discussion about loose grips which was never even brought up. The best answer is use whatever you think works best for you until you want to improve. At that
point, something has to change & often several changes needed. Always be open to change or accept the status quo.