I imagine there would be achievements tied to plunder the vaults either through sneakery or violence. With the new AI where there are guard changes or people going into the vaults to make deposits or withdrawls, there is more scope for thievery too. imagine if you could kill a rich trader or noble, disguise yourself as them and then stroll in! Kinda Oceans 11 style.
The relevant guild should also recognise such achievement and either approach you for recruitment (like the DB did in Ob after your first murder) or should recognise it with a special reward (nothing huge, could be maybe a unique cloak or pendant or badge or something)
Ordinators were great, i loved their callous rudeness toward you and how they'd attack you in a religious frenzy if you wore their armour or when you're declared as the nerevarine. I collected a pile of ordinator helments and displayed them in my house in MW