Starting with a caveat; I am no master GM, I'm a barely competent player, and I can't even play the cello (last one is less relevant to this post, though). Consequently, take what follows with a grain of salt. Like, a really big one. Rough size and density of Betelgeuse, in fact. Imagine a plane of existence whose full substance was nothing but NaCl. That kind of grain of salt.
So, yeah. On to the question at hand; 4e and Pathfinder.
I played the old 3.5, from both in front of and behind the GM's screen. It had a certain texture, mechanically, which for me could be perversely rewarding as a player and unendingly frustrating as a GM. Building custom monsters was tough, certain rule interactions required massive oversight, and spellslingers in general found themselves somewhere between 'Awesome McCooljoe' and 'Unholy Power Nexus of Unlimited Potential'.
I am generalizing, but stick with me. Or read some classic literature, I seriously wouldn't hold it against you and your time would likely be better spent there.
When 4e rolled around, I found a lot of that ironed out. The races are simple in execution, and interact intuitively with classes. The classes (for the most part) make sense. A fighter does largely what I imagine a fighter could do. Similarly, rogue. Wizards feel wizardy. In short, each class has a carved niche (again, for the most part) into which they slot. That said, multi-classing is a hassle. And I think it is a hassle for the precise reasons above; each class already has a niche, so multiclassing in 4e sometimes feels like a home DIY project while slightly inebriated. I knew what I wanted to do, but I was working against what someone else had built. And the person who had built it was a lot smarter than me, when it came to numbers. And also what I thought was a studfinder turned out to be the garage-door-opener. So now my girlfriend is mad becuase I also knocked down a wall which turned out to be the back of her closet? And we got into a fight about dinner with the folks (how was I supposed to know her parents only drink white zinfindel?) so now I'm sleeping on the couch.
I kinda lost the analogy there. Back on track.
4e's strength, for me, is that it doesn't lose the forest for the trees. All elements seem designed (successfully or not) towards a game system which is easily accessed, utilized, and executed.
That is also 4e's weakness because, frankly, some trees are cool. For some people, the tree is more important than the forest. In 3.5, you can make spells! That's cool! Is it balanced? Sometimes (a lot of the time) it isn't. But for some people that is both desirable and forgivable.
Pathfinder attempted to find a nice middle-ground. Wizards are no longer squishy meatballs for the first couple levels, and warriors no longer stand in front of the wizards at high levels wondering what else they could do (HUGE generalizations there, please don't kill me). It has texture and isn't woefully unbalanced.
Is it better than 4e? Not the point of this thread, and beyond my purview anyway. I play 4e and I have fun. I play Pathfinder and I have fun. I have found GMing easier to do in 4e.
Best advice I've read on here is to know your group. I would suggest discussing with them their specific qualms with each system, and possibly take whatever steps you can to ameliorate them.
Good luck, in any case.