The new memory management features are working extremely well!. I have a MBA with 4 gigs of ram. With mavericks it never touches swap, and it takes quite a lot of apps open to even make the memory compression go into effect. The cacheing seems very intelligent as well, the system always uses just under 4 gigs of ram and is very snappy when multitasking compared to lion, makes great use of all available memory. I'm very impressed with what they've done under the hood with this release. Safari also seems to take far less memory than safari 6 in ML. Safari 6 "safari web content" process often used 600+mb of ram for me with just a few tabs open. Safari 7 has more web content processes but they all use very little ram, and the overall usage is far less than safari 6. This release will be a must have for anyone with <8gb ram.