@Estel
It's a class 2 8GB card that came with an Xperia X10. I am not quite ready to start repartitioning the eMMC, and I'm also hesitant to put swap on microSD, but I do have a class 4 4GB card, maybe I'll try using that.

@mscion and debernardis:
I repeated the exact same test for starting from a partition from within Maemo, and then a few more times without rebooting. I did not use Close Debian.
1st: 1:20min (loading OO took 35secs)
2nd: 1:05min (loading OO took 15secs)
3rd: 1:10min
4th: 1:05min
Then I did the same once more (without rebooting), O/Ced too 1150MHz, this took 55 sec.

mscion, for the original test I did record the time it took to start OO. With the image file on MyDocs, from within Maemo, it was 55secs.


But after a few days of use I must say that the responsiveness improvement is just as nice as, or even nicer than the loading time improvement. ED is now really usable, the lag is pretty much gone.
So using a dedicated partition is highly recommended.