I'm using A2SD+ on my HTC Desire running on MIUI.
Currently only the app and app-private are under /sd-ext, but I'm running out of space very quickly :)
Currently my dalvik-cache consumes 46.3MB and the data takes 53.7MB of internal phone memory, so I think data will give me more value, but I'm not 100% sure of that either.
I know I can technically move both data and dalvik-cache to /sd-ext, but I understood there could be performance problems, but I need the space. So my question is which will have a lesser effect on performance? Moving the data or the dalvik-cache?
EDIT: Some tech info (if it helps):
My SD Card - Kingmax, Class 10, 16GB
I tested with SD Tools and got these results:
Writing Speed: 8.7 MB/s
Reading Speed: 18.6 MB/s
Note that the test was on the FAT32 partition, I don't know if the EXT3 partition I use for the /sd-ext will be any faster. The /sd-ext partition is 1GB.