My biggest issue (and yes, I'm not the first to say this) is that with this system, you seem to lose the ability to be really bad at something. Both as a player and a DM, I find that characters are defined both at what they're really good at and what they're really bad at. I mean, I've had high level characters who still had -1 in certain skills.
What if I want to make a clumsy spellcaster who sucks in acrobatics no matter how strong his spells become? Or someone who just can't swim at all and would drown in 8 feet of still water? Or someone who couldn't distinguish north from south even with a compass in hand? Adding level to checks gives you a certain level of capability in everything, meaning you would lose this part of the game. And in my opinion, being bad at things is equally wonderful as being good at things. It's what makes the game real, and makes you appriciate whatever your character is good at.
