Found this article which gives a different perspective
To "Gi" Or Not To "Gi"
A JKD Perspective
By Armando Basulto
P.F.S. Full Instructor
East Coast JKD/FMA
June 11, 1999
In the last decade, the status quo of the martial arts world has been shaken at the foundations by the emergence of the Gracie family and their particular brand of Brazilian Jiu Jitsu. Though the Brazilian Jiu Jitsu challenge scene had been in existence in Rio for over thirty years, it was the new crop of Ultimate Fighting Challenge and other No Holds Barred competitions that thrust BJJ into the spotlight. All of a sudden, there was a mad rush by martial artists everywhere for good training in groundfighting and grappling.
Within the Jeet Kune Do Concepts community, Brazilian Jiu Jitsu has been incorporated into an already existing groundfighting curriculum. In the spirit of "absorbing what is useful" and training as realistically as possible, we have taken the techniques, strategies, and submissions of BJJ and downplayed those elements which could be viewed as "limitations" or "ways." To this end, martial artists incorporating BJJ into their JKD program train the greater part of the time without the traditional kimono or "gi," and opt instead to train with just a T-shirt or bareback. Though it remains true that a greater portion of training time should be done without the confines of traditional uniforms, rules, and formalities, there are some benefits to training with the Gi that should not be overlooked.
Firstly and most obviously, except for those folks lucky enough to live in warm weather year round, T-shirts are not the uniform of the day all year long. In New York City, we wear coats and jackets at least nine months out of the year. If our goal is to train in conditions closest to the most probable scenario, then sparring in just a T- shirt (or no shirt at all) would be most unrealistic. Sparring with the Gi on allows one to not only train chokes that are easily recreated with a jacket or coat, but also opens up a myriad of other sleeve and lapel controls. If possible, training can be done while wearing the coats or jackets themselves. Even though it can get hot and uncomfortable (and zippers and buttons can be hazardous), it is something everyone in search of realistic scenario training should attempt.
Secondly, sparring with the Gi can actually be more difficult than without. Though you will definitely have more techniques and chokes available to you for attacking, you will also have to defend from these same techniques which are now available to your opponent. Now that you have sleeves and lapels to grip, it's possible to work the open or "spider guard" and attempt sweeps and reversals, but your opponent now has sleeves and lapels to grab on you, making every reversal or transition three times harder! As an experiment, spar with a partner with Gi's on for five minutes, then strip off the kimonos and continue for another five minutes. You may be surprised at your increased speed and fluidity.
You can take it one step further and spar within the confines of a Brazilian Jiu Jitsu Tournament. The rules of the BJJ tournament emphasize proficiency in the skills (i.e. attributes) of groundfighting/ grappling. Though there has been some talk that the tournament competition has actually hurt BJJ's effectiveness and has diluted the art, it is in this environment that the real artistry of the good Jiu Jitsu player can be glimpsed. Points are awarded for obtaining the dominant position (like the MOUNT or TAKING THE BACK), or for sweeping or taking down your opponent. Though, obviously, the end goal is to get your opponent in a submission, thus ending the match, this type of training rewards one for "dominating" the fight either by jockeying for positions or keeping your opponent constantly defending. This will inevitably make one a better grappler & groundfighter. Too often, people with only a "Cliff's Notes" knowledge of Jiu Jitsu waste precious energy struggling (in conflict with JKD's conservation of energy and effort) to get that armlock or choke before they're actually in the proper position. Sometimes it may be more fruitful to simply sweep or reverse someone who has taken you to the ground, and place yourself in a better position to deal with possible multiple opponents rather than getting tunnel vision while concentrating on getting that fancy armlock.
I am by no means advocating that everyone run out and purchase the $300.00 Brazilian-imported "kimonos" covered with patches and the name emblazoned on the back. The current recommendation to train 80-90 percent of the time without a Gi still holds true. But when you do don the white kimono the other 10 or 20 percent of the time, you should make it as productive as possible and know how to utilize it for maximum attribute development. Though the sin of growing too dependent on the Gi is a much greater crime than lacking the experience of sparring with a Gi, there are many benefits and lessons to be learned by trying to work within the Brazilian Jiu Jitsu tournament scenario and its uniform...the Gi.