Replacing driver's seat
 

im a new fit '11 owner and am curious if people have replaced their driver's seat with something more comfortable (upgrade)?

Well, I replaced mine with the seat from a Scion tC. I couldn't get it separate from the Scion though, so I got the rest of it too.

(I feel ya - it's been discussed at length on here, but unless you are are short (i.e. under 5'8 or so), the seats aren't the best.

Specific issues:
1 Seats are fairly narrow
2 Bottom cushion is short
3 rearward travel is very limited.
4 no ability to adjust height
5 padding is extremely soft.
6 seat frame can be felt through padding (right along the seam between the main part of the seat and the side bolsters)

Solutions:
1 - none short of replacing the seat.
2 - none short of replacing the seat
3 - gas pedal can be adjusted to allow more fore-aft room to pedal, but the brake pedal can't, and it doesn't help much.
4 - you can use shims, but it will leave the seat a bit misalligned (the front bolts are at different angles, so adding a washer to each side will lift the front right while moving the front left up and slightly forward. Depending on thickness, it can become quite noticable)
5 - I found no solution that was satisfactory. The center of the seat seemed to get softer over time as well, compared to the passenger side which rarely had an occupant)
6 - I used Clazzio seat covers with a layer of terrycloth to provide a buffer. It also helped a bit with the padding too soft issue.

I liked my Fit overall - my inability to get comfortable in it after continued effort was the main reason I traded it in. A car can be terrific, but if it doesn't fit you, it doesn't fit you.