Another vote for the full size Grip'. I have a mini, and I like it, but there are times when it feels a little small, both in blade length, and handle chord.
Every knife is a compromise between various factors, and a bigger bolder is going to take up more space in your pocket. If your knife needs are mostly limited to what you would see in an office job (envelopes, stubborn snack bags and the occaisional padded mailing envelope), then the mini is probably the better choice, because it's easier to carry. Or, if you're able to back it up with a 3.5" to 4.5" fixed blade.
If you work outside, or someplace like a warehouse where your knife gets frequent, intermittent use all day, then the big Grip' is the way to go. Likewise, if your off-time is spent in the yard, garden, or wilderness spaces.