im an optimization freak though, I restarted my oblivion when i realized my umbra sword was actually a gimp version. first thing i did this game was find a talent calculator
items are fixed in their stats, however has you progress skills such as one handed, heavy armor, smithing (for the upgrade amounts) and enchanting (for higher enchanted bonuses) you will be able to get more use of their base stats as well as upgrade them more.
furthermore as you gain levels when entering a new area the area is locked to that level, and so is the loot, as you lock areas at higher level loot quality will be better.
a note is if you use items of higher quality at lower level, for exemple steel/orchish in lvl 1-10 you will feel more powerfull because mob skills and stats ratios are set for lower tiers of equipment, thats about all I can think of in the matter.