I think underlying beneath every chopper lies this simple wonderment: who is the best?
That's a solid question. A worthy question to give it a shot at tackling. I'd certainly like to know.
I say you can measure the artist and their works. Yes, it is true that quantifying an art piece falls into the realm of personal preference. However, this realm isn't as out there or as daunting as it may first seem - Gather the collaborative personal preferences from a mass of peers in a community like this then the data becomes quantifiable and viable. 1000's of personal opinions put together is tangible data, and with it you can see trends, you can see what is the most popular chosen piece of art within the community. You'll ask yourself, Why is so and so's chop number 1? The answer is because the community said so. And that community just happens to be built up of artists with similar perceptions/preferences/skillsets etc like yourself, so that data, all their opinions crunched together, clearly means something.
The ranking is a joint collaboration of personal preferences all added up. I.e. a huge culmination of all opinions in the community. What better way to answer that aforementioned question of 'who is the best' proposed in the first sentence.
How do they rate videos on youtube? Same principle: a rating system (however, even they have dumbed it down now to a simple like/dislike feature. Not a 1-5star rating system anymore).
Also a comprehensive ranking system like one that has been proposed resolves a lot of staff overhead of admin having to determine manually who is to be ranked up and who isn't. It also means we've got data to back up our actions: i.e. when we refuse to promote somebody up who's been nagging and nagging us, we can say look: your ranking/avg rating shows that the community agrees with us. That's important and means we can justify our actions (or lack thereof).
As long as the algorithm is correct it will be the most accurate way of going about it too.
Keep in mind, as it is now chopper levelling is governed by admins personal preference and opinion right now anyway.... So this whole 'personal preference' thing is around already. We're simply taking it off the hands of the admin and extending the control out to the community.
Global rankings are good, as choppers it gives you a solid foundation to see and watch your progress over time. You can see yourself literally climbing the ranks one rung (or ten or fifty) at a time.
Lastly, and most importantly, is the key principle about this is it rewards active members of the community. It will enhance activity rates, it will be fun for users, and that is important for the growth and longevity of this community and for it to prosper.
If that all isn't enough justifiable information for giving this a shot I don't know what is! For me, just falling back to that age old question at the top of this post is worthy enough of giving it a crack in itself.