If I create the cuspidal newspace of level 11025, weight 2 trivial character using Snew=mfinit([11025,2],0) , which has dimension 317, and then compute some Hecke matrices, they take an enormous amount of time: several days for mfheckemat(Snew,29). Why?
My own C++ modular symbols code can compute all Tp for p<100 in a few seconds, admittedly on the whole space (dimension 1684) not the newspace.
Overall the new mf* functionality is fantastically useful -- but some spaces take orders of magnitude longer than other apparently similar ones, and it would be nice to understand why.