Hello,
Maybe your friend just loaded 128 samples but also all his memory was filled up? Because you actually have the same number of samples (8192) available in regular 4tone mode, ive looked into it...
About the conversion? it goes as swift as ever, I mean the actual loading process is there wich can be upto beyond a minute or 2 if you load like 50 mb or so.. but thats "load activity" I've never witnessed "conversion activity".. They are instantly "there" when their loaded.
You can even preview and *.as (akai) sample when you are in the load screen, and then use the AP (patch) to begin loading and converting in user area.
cd