The intermittent odd numbered Tiers are rarely if ever used for more than a passing phase. The rapid advances and constant replacement of items doesn't add a proper sense of progress to character advancement. Items have more of a meaning if they are kept for longer periods of time.

[CODE]New Item Rank Old Item Rank
I I-II
II III-IV
III V-VI
IV VII-VIII
V IX-X
VI XI-XII[/CODE]

The even numbered Tiers in the current system could be maintained by dumping the odd Tier items and renaming the even Tier.

Its just a leftover from the old leveling system, back when it took more than a day to reach cap
It certainly something to look at after some more important things are addressed
Though I would suggest a split between the old system and your proposed system
Change the lower level items but leave the higher level stuff alone