PF Samurai in 3.5

[Elitist]

So after realizing how weak the 3.5e Samurai is the hard way, my DM quite graciously allowed me to switch my character to the PF Samurai. I've never had experience with PF classes in a 3.5e campaign, so this will be interesting for me.
I've looked over the PF Samurai but I'm not sure what to make of it. Is it worth it to make the change? Is there anything interesting I can do with the character's class now that he's a PF class? And of course, any advice with this new class?

[Psyren]

The PF Samurai as you know is mainly just a reskinning of the Cavalier class from the APG. Comparing the two, the PF Samurai is a bit stronger than the 3.5 one but that still isn't saying much. I'd put it roughly on par with a Barbarian if it can make proper use of the mount; if not, go with the Sword Saint archetype (which gives you a very limited bonus damage ability; not great, but if you can't use the mount, better than nothing and stacks with your Challenge bonus.) Either way you'll still typically be no higher than T4.

The main interesting thing is the mount, which in PF works exactly like a Druid's animal companion - i.e. it can learn feats, tricks and even archetypes so it can better help out in combat. If you're a Small Samurai it can be a wolf (which arguably opens up Dire Wolf to medium ones, though that one requires DM approval) letting you take it with you into dungeons and the like and benefit from its heightened senses.

Their second interesting ability is Challenge, which is basically an Ex Smite that Samurai and Cavaliers get. Like Smite, you mark a target and get to add your level to all the damage you do. Unlike Smite, this ability doesn't care about the target's alignment, but instead you lose AC vs. other attackers and get no smite bonus to hit. Challenge also interacts with your choice of Order in some ways, e.g. Order of the Warrior gives you scaling DR/- vs. your challenge target's attacks. So, like the Paladin, this guy does better against single tough foes than against a mob of weaker ones.

Their third interesting ability is Resolve, an X/day defensive ability. This lets you shrug off various status effects, reroll fort and will saves, stay conscious into negatives, and later avoid death itself.

Other than those three things they are basically fighters.