You can leave anytime during those 180 days and when you get back you get another 180 days.
A lot of people seem to think that they're stuck in Thailand for the entire duration of their stamp.
And yes, you can get ONE 180 day extension per entry, but the process requires the same documents you used when applying for the visa, so its easier to just fly out and in.
The soft power visa application isn't faster. The time it takes depends on your individual application details and the embassy staff, not what you base your application on.