Sorry to disappoint, this isn't another complaint thread.
Who can generate the most hate?
Let's take a look at the match-up.
Gladiator
Heavy Slash
Heavy Stab
Provoke
Phalanx
Riot Blade
Marauder
Full Swing
Steadfast
Defender
Disorient
Warmonger
Storm's Path
Intimidation
In a practical situation both will be able to use many skills that the other class has, so I highlighted the ones that are unique.
Although Riot Blade builds a ton of hate, it cannot be used often due to it's recast time and the 2000+ TP cost. So Marauder has the upper hand using Storm's Path with it's 1500 TP cost and 10 second recast.
But, if the Gladiator is able to time their shield skills so at least one of them is always up, they may actually not only build more hate with Phalanx, but also out damage a Marauder. Phalanx comes at a mere cost of 250TP and a 5 second recast for a decent amount of damage. Although it may not build more hate than Storm's Path, it could be used much more often during a fight.
So in the battle of GLA Vs MRD, the Sentinel wins!