earmv4 packages coming soon

Hi, all,

I've never been quite sure about the differences between earm (earmv5) and 
earmv4, but since earmv5 packages won't run on earmv4, I've started a bulk 
build of earmv4 packages.

Which makes me wonder: is there any downside to running earmv4 packages on 
earmv5? Does earmv5 make use of features that significantly improve 
performance over the same earmv4 code?

If there is no significant improvement to running earmv5 specific 
packages, then I might just build earmv4 instead.

Also, not that this matters much, but build.sh with -m evbarm -a earmv4 
doesn't work, although -m shark does (and I'm sure -m hpcarm and friends 
work, too).

Thanks,
John