By all accounts the Corbin seat appears to actually make it worse. I've successfully carved a few inches off the seat foam insert using an electric carving knife then smoothed the foam with fine abrasive paper. The vinyl cover can be carefully stapled back on or glued using contact adhesive.
I have the corbin, and I am 5'5. I still cannot sit flat footed, but my feet do touch more of the ground than with the stock seat. The key to it is to have Corbin do a "nose job" on the new seat. This cuts out the width that makes it feel like it is taller. In actual measurements, the Corbin is a good inch or 2 lower in the saddle. When at a stop sign, I'd say it's at least 1/2 to maybe an inch lower with the "nose job" on the Corbin. It's surprising how much that can help, but it does!
I'm soon to inherit my husband's ZRX and I'll be getting a nose job done to a new Corbin for that bike.
There are also several other people here who had the nose job done and who agree with me. It helps get your feet more on the ground....order it...it's worth it. They will know exactly what you are talking about!