As a developer I would say no. This is because applications (and even web-sites like Google) can use their application folders extensivly and as time goes on Microsoft are encouraging developers to go away from the registry as a information store (using application folders (
SpecialFolders) instead. This will mean these folders are used more and more. With the overhead of NTFS compression and un-compression (in my oppinion) to compress these directories would not be wise. Microsoft say:
"Because NTFS compression is processor-intensive, the performance cost is more noticeable on servers, which are frequently processor-bound. Heavily loaded servers with a lot of write traffic are poor candidates for data compression. However, you may not experience significant performance degradation with read-only, read-mostly, or lightly loaded servers.
If you run a program that uses transaction logging and that constantly writes to a database or log, configure the program to store its files on a volume that is not compressed. If a program modifies data through mapped sections in a compressed file, the program can produce "dirty" pages faster than the mapped writer can write them. Programs such as Microsoft Message Queuing (also known as MSMQ) do not work with NTFS compression because of this issue.
Because user home folders and roaming profiles use lots of read and write operations, Microsoft recommends that you put user home folders and roaming profiles on a volume that does not have NTFS compression on the parent folder or on the volume root. Individual users may still enable compression on their folders, but the overall number of compressed files and folders is smaller. On servers that host compressed volumes, you should use careful performance monitoring to determine whether the CPU has enough capacity to support the compress/decompress operations that are being performed."
I hope this helps.