I'm a huge proponent of the values of hands on BattleMechs, and TacOps is the hand-fan's best friend!
There are simply so many things you can do with hands....
They help you 'Mech stand up more easily from a fall.... (TacOps, pg.25)
They can be used to climb up steeper cliffs than a 'Mech can normally traverse....(TacOps, pg.22)
They can be used to crawl to cover if you've suffered leg damage....(TacOps, pg.20)
You may pick up enemy equipment and steal it in a raid.....
You may pick up friendly equipment and evacuate it easily in the event of an enemy surprise attack.....
You may pick up an enemy's blown off limb and beat him with it for extra humiliation factor.....
You may pick up ProtoMechs, battle armor and small vehicles and throw them...... (TacOps pg.92)
You may drag a valuable but damaged friendly unit off the field to prevent it's capture.... (TacOps pg.99)
They may be used to grab and grapple an enemy unit, preventing it's escape or to prevent it from effectively using it's weapons...... (TacOps pg.90)
And finally, the presence of hands allows a 'Mech to have a basic Omni-like capacity via it's own ability to lift hand-held weapons. Close combat 'Mech need the ability to attack at a distance? Handheld LRM racks. Conventional 'Mech need a weapon it can use underwater? Handheld torpedos. Need an artillery spotter? Handheld TAG. Need a minefield? Handheld Thunder-LRM launcher, etc.
And you get ALL THIS for ZERO tons and just ONE critical slot! Quite frankly, the hand can be one of the most useful pieces of equipment on a 'Mech, and my preference is always to have at least one, if not both.