upgrade saddle / seat post on Dahon d7
So, i have had my dahon mariner d7 for a few now, but the seat is unforgiving around town. I was thinking about maybe replacing the seat at some point. i have read a bunch online about upgrading the seat (saddle), a "thudbuster" (if they make one the size of the dahon seat post?) , the Biologic Suspension Seat Post, etc. I need a comfort ride but i also don't want to be jiggling around like jello cup. i was leaning towards a new seat, i find that the Brooks b67 is good? (Hard to believe after seeing it in person) and i find it a bit pricey.. i was wondering if any of you guys have had similar situation or have any recommendations / Experiences ?