"mudgel"
I have an exclusive DAW which also has Video/graphics etc software as this is my pro rig for Audio, Video & 3D/graphics.
Perhaps my needs are unusually large by comparison with other users and my only real answer is to get a much bigger SSD drive for my needs.
Seems to me like you have already answered your question.
I use a 120GB Vertex 3 SSD drive for the OS on a dedicated audio-only DAW. A clean install of W7 Pro x64 is 10GBs. Add another 20GBs for music apps. only..., libraries are on high performance mechanical drives (cost considerations). That leaves quite a bit of wiggle room for growth. I also do not intend to fill up this SSD as it is strongly recommended to always have at least 20 to 30% free space for the SSD to do its thing optimally. Also, with SSDs, the following guidelines may be obvious to some and not so obvious to others.
Simple Dont's with SSDs:
1] Don't full format an SSD. You should always use quick format only.
2] Don't run too many Benchmarks.
3] Don't fill your SSD beyond 80 percent capacity of the available flash space.
4] Don't defrag your SSD.
Do I need to enable TRIM on my SSD?
No. TRIM is automatically enabled in Windows 7, but to verify that TRIM is either enabled/disabled, follow these steps. TRIM is not currently available with MAC OS.
1] Type "cmd" in the start menu search box
2] Right click the cmd program and select run as Administrator
3] Type the following in the command line (omit quotation marks)
"fsutil behavior query DisableDeleteNotify"
4] TRIM is Enabled when DisableDeleteNotify = 0
5] TRIM is Disabled when DisableDeleteNotify = 1
ref: http://blogs.msdn.com/b/e7/archive/2009/05/05/support-and-q-a-for-solid-state-drives-and.aspx