I have found that maemo usually swaps out about 40MB of rarely used ram pages. That's why I insist in 64MB, and for that reason 24MB is certainly a too small swap size to maximize performance.
By using ramzswap you win speed and responsiveness when reading those pages back (switching programs), and much reduced mmc wear (if that bothers you), at the cost of a little less ram.
Just try several settings and find what maximize performance for your usage. As I already said, 64+64 is ideal for me.
"free", "cat /proc/swaps" and "cat /proc/ramzswap" will provide you with all information you need