Does anyone find the unisystem a bit unsuited for high powered characters. It seems way too easy for characters with any competence in a skill to succeed at even the most difficult of checks. Any fixes?
Actually, I've found that "average" skill levels tend to generate as much failer during stress as success. It's only when people become hyper-competent with very high skills (or are extremely powerful supernatural creatures with insanely high attributes) that failure becomes a thing of the past, at least for anything but the toughest tasks.
I'm not really entirely bothered by that. Someone who is a master of, say, Research isn't going to fail to find basic informaiton on something unless it's really, really obscure.
If you find that players tend to be too competent or powerful, you can either make their opposition just as skilled or increase the difficulty of their rolls. Penalties can go a long way, as can requiring a certain minimum level of success to achieve the desired result.
Never had a problem with high-powered characters. There's so much in the game that can tear you a new one no matter how high your skill is that it doesn't really matter. Sure, you've got a great Dodge, or Firearms, or Sword skill, but that ain't gonna save ya when El Dios Loco del Momento pops up and decides your general tri-county area is now lunch. Or when you're try to elude a Relentless Dead.
Sure, you can kick the butt of any mortal, but mortals never are much of a problem for a high-powered witch/warlock/inspired anyway. It ain't the raw power, it's the finesse that allows characters to survive. Power is all well and good, but nobody goes mano-a-mano with the Big Nasty alone if they're anywhere near smart. A cooperative group of powerful Gifted is going to roll over/through any normal opposition by their very nature, but they will be forced to actually think when confronting supernatural threats, most of which can't be put down by simpe guns 'n' fireballs attacks.
At least, that's how it's played out in the games I've been in.
I have no problems with Unisystem skill rules as they are. I believe your main concern is the fact that is easy to create a character with a stat of 4 and a skill of 5, giving him 90% chance in being sucessful in a skill check. Well, most people are proficient up to this level in their profession of choice. As such, I don't really think of this as a problem.