The 225i have better pads (L-Cush), better matched drivers, better airflow (wire grills) and a better cable with 1/8 plug.
If I was using at home (non-portable system) I would spring for the 225i.
If I was using with portable system the 80i or MS1 are fine, especially as you then don't need 3.5mm adapter - but you'll likely end up buying the L-Cush pads anyway...
I've grown to realize that there are some people who don't like the 8-conductor Grado cable. A few years back, I thought the cable was the end-all, be-all, but not as much lately. I guess my feelings changed since I'm capable of making an solid intermediate cable that's upgrade over the basic 4-conductor Grado cable, yet have a bit more flexibility than the 8-conductor cable, as well as creating a custom length that is not too long, or too short.
But, having the original items - good cable, etc. is almost essential if you want to resell the headphones. Some people love customizations when done. Others, not as much and tend to prefer stock (virgins) so they can then adjust and apply mods as needed from their perspective.