Ditto what Ralphie said.
John mules will seem to test you more,but are more stable. I prefer them to mollies, although the last two I bred came out mollies and you can't shove them back and ask for new plumbing. There are good and bad things to say about both. Get a molly that is bitchy during her cycle and it's not fun.
A 15-18 yr ld mule still has at least 10 years work ahead of it if not more and one of you should know whats going on. My pack mule is 28. It's a darn site easier if you don't know and the mule does vs the opposite.
If packing I prefer one 13&1/2-14 hds. The big ones can't carry all that much more and are a darn site harder to lift packs up on.
