First go and watch or train with them.
I have never trained with him, or any of his students, but there is plenty of information on his training methods floating around the internet. From conversations with several of his long term students, it seems that they actualy do spar, but it is with excessive safety gear, including goggles, a diaper like groin protector, and chest gear, and they will tell you that they "fight" but do not spar, as sparring is not real fighting.
They use those 1970's enter the dragon Kenpo boxing gloves (Shitty in 1970, even shittier now considering MMA gloves). They use this gear because there sparring is full contact, all targets, full speed. They have a very RBSD approach to JKD.
Tommy's lineage is endorsed by the late Jesse Glover, and Ted Wong, Bruce Lee's first and last students, though he did not train with either for an extended length of time. Tommy has a combatives background, and so a lot of his JKD looks more like combatives than what is in the states. From what I hear, the training is intense and sort of like Krav Maga with a JKD base(sorta).
It realy depends on what your looking for, if you want the original JKD as used by the founder, I would go to Steve Smith with Progressive JKD, trained by Jerry Poteet, and Dane Junod(who is the only person ever fully certified in Jerry Poteet's and Ted Wong's JKD). To sum it up, Steve's program could help you develop a striking base for competition as well as self defense, Tommy's JKD will not likely prepare you for any competition, and the students have a kind of Too Deadly for the ring attitude.
Check out the Wednesday Night Group's stuff, and what they have to say about Tommy, he has trained with them and the WNG is pretty legit as far as JKD goes, having had students participate in full contact kickboxing.