Imo now armor and horses (expect tank horses because no one uses them thus it's hard to tell) would be balanced even without upkeep. We are limited in levels so heavily armored people are slow. Before January, we had helicopter tincans because those guys were level 40 and had like 300 wpf. Now with wpf bonus removed and level cap, armor choice is a matter of tradeoff, even without any upkeep.
Upkeep was overkill and didn't adressed any issue by itself. Level cap and retirement massive nerf (heirlooms nerf, wpf bonus removed, xp bonus lowered...) were enough to make all types of armor attractive. Changes on riding skill requirement where weird and fucked things up as nearly every cav can ride a PC without gimping themselves now. If horse requirements and agi per riding skill were returned to prepatch values, we could safely remove upkeep altogether as a PC build would mean 30 agility again.