There is a hack to get around this (in Chrome) by increasing the SDP channels transfer rate (I think), still doesn't solve the MTU/reliable issue though. I originally found it via ShareFest - https://github.com/Peer5/ShareFest/issues/10 & have it integrated (in library form) here - https://github.com/erbbysam/webRTC-data.io
I haven't tested this yet on Chrome Stable though.