Haha, this post brings back good memories of when I was 14 and helping my dad pull out stumps with my (his) suburban. The truck was in 4wd, and he hooked up the chain and said, "okay, go...but slowly." I sat there and ever so gently tried to press the gas pedal. The truck didn't move nor the rpms really climb, so my dad said, "Stephen, you can go!" as if I didn't hear him the first time. Then, when I finally did go, I did exactly that, GO! The pedal would reach that stiff "breaking point" and I had that stump pulled out in a nanosecond. Needless to say, I was more careful the following times.
The suburban I drive now is the same one although modified. Nothing has been done to the throttle cable/tbi unit since then, but I've got a lot of control over the throttle now. I guess it just takes getting used to.
If it's overly stiff or sticky in certain parts, another thing to do is go wiggle the throttle linkage at the tbi unit. If it moves around a lot, you could have an ovaled bushing hole in the tbi unit and, as far as I know, the only fix for that is a replacement tb.