With PeterK's icon.library, Matt Hey's CopyMem routines, ThoR's stuff, Mathias Henze's HSMathLibs and Oliver Robert's WarpDT datatypes, AROS m68k would be much better than it is now.
It's a shame the dos.library/scsi.device/graphics.library stuff on EAB can't be used as they are Resourced from the copyrighted CBM versions. 
im not sure if peter.k icon lib wasnt resourced as well, only that the complete code has been replaced. now i dont know what the situation legally is. however as the work was not based on any sources, only on reverse engineering of binary and since the current library does not contain copyrighted code its okay i guess.
its possible to use this library anyway and it gives nice speedup.
what concerns math libs i have never been sure how much do they improve upon genuine ones. at least integer wise aros is currently on the same level as aos afair. have to check for fp.
as for warp datatypes these are commercial, you can surely use them under aros 68k as you do on aos, no doubt, you just need to buy them.
all in all there are few aspects aros has serious performance problem. one of them has just been traced doen to a particular function within graphics library, seems toni has problems to improve it though. i will try to make it more public on the dev list.