A mixture of the two techniques allows you to fully utilize the potential of the Tori.
By holding all you can keep the general momentum that your Tori has gathered after having started moving, by relaxing certain joints,
in combination with rotation etc, you can turn your Tori into a lethal combatant. Hold all can also be used to absorb great momentum,
for example the Tori's elbow can bend when it comes into contact with an object. Forcing the elbow to absorb the momentum gives
reassurance that the shoulder or pec won't take the brunt of the force. Unlike if the elbow was extended, the shoulder, pec and elbow
would jolt on impact, causing possible fractures or dismemberments.
Relax all of the Tori's joints can be used when your Tori has been pushed away, allowing the limbs to move freely and it can be much easier to form an advantageous position.
Yes it is true that relaxing all of the Tori's joints is visually much more appealing, but if you are able to mimic realistic movements
(by relaxing pecs/chest/shoulders/elbows at certain times) it can be much easier to look 'like a pro' and at the same time be
efficient and aggressive.
-Deut