On 7.104, it consistently had memory usage at roughly 95% or higher for a 512MB RAM module. It was always right on the cusp of running out of wired RAM. I was seriously concerned that any further updates would be precluded by insufficient memory.
However, with 7.190 the usage is drastically reduced. I run all the same services, yet my memory usage currently is at 440MB, or 74%. Swap usage is currently 4% of 1GB.
I am positively thrilled with this new beta.