Mine

Emc2's trajectory control has been totally rewriten.  It has fixed quite a few of the bugs from the original emc planner. You can read about it here.
http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?TrajectoryControl

It supports g61, g64 and g64 px.xxxx(blend tolerance mode)
You probably want to try blend tolerance mode as emc takes all the short line segments that fall within the P tolerance and creates larger line segments.  

I have no experience with mach to compare