Or rather, yes. It gives you Roleplaying value - many players roleplay brawling as learning or practicing a specific fighting style or martial art, existing or fictitious. These then can be added to your background and used to justify a high rank in Unarmed Combat. It might not give you any physical advantage over others by itself, but it makes you a better player by making your character more defined and realistic. Many people value this a lot in this game. Others just care about the monies.
Currently, I'd suggest hiring 2 brawlers and 1 medic. If you are level 3 or 4 or lower you're lucky to get more than 2 or 3 fights a day otherwise. A medic can heal you and allow you to fight up to 5 times a day as Hal stated.
As it is, when I travel with both my Bodyguards and my medic I gain an average of 15-20 xp per day Sparing 5 times, and it costs me about 750 credits a day for healing. When I travel with just my personal bodygaurd, I can spar at most 2 or 3 times and get around 6-10 XP per day.
____________
Warning this is strictly Orions McPhees Opinion, it may or may not have any bearing on events true or imagined
Player medical skills are not implemented yet, so no. To the best of my knowledge, droid healing and medical item healing are not implemented yet either. So, currently as far as I know, the two ways to heal are naturally and with a NPC Medic.
____________
Warning this is strictly Orions McPhees Opinion, it may or may not have any bearing on events true or imagined
You won't be able to do anything while using medical items on yourself (most likely also when using them on someone else), so you can prolong the sparring practice.
However, since the duration of the brawling session doesn't affect XP, I fail to see the point.
With my stats I can reasonably expect to get through 2 or 3 brawls before I run out of HP, though today I did get my full quota of 5 in without using my medic.
So, those of use with less HP or stats less suited to brawling, the ability to enhance healing is very helpful to allow a full sparring session.
It is even possible for a level 1 or 2 to run from a fight, heal then resume. The NPC will not have recovered any HP at that point.
____________
Warning this is strictly Orions McPhees Opinion, it may or may not have any bearing on events true or imagined