Have you ever tried a seat or just listening to the much worn out opinions of others who have (probably) never tried a seat either?
Seats have less manourvreability (generally - unless you splurge for a Dynabar) but if you are still muckin about with your kite high, that is simply not a factor at your skill level. Not trying to be harsh but that's where it's at Opti.
Also, for less than $200 you can have a seat harness that is more realistic to your skill level (not that of seasoned riders who loathe seats - having never tried one

) and in a season or so you can sell it and probably get half ya money back selling it on SB.
Might be worth the expense, because if a waist harny is ending your sesh, then being able to ride on longer with a seat would be worth the small change IMO.