I wouldn't get over excited about the Ro-Ro capability if I were you. Yes there's a ramp and a ramp support pontoon which allows it to interface with LCVP5 and LCU.
Trouble is, the VP's are usually kitted out with Arctic shelters, which makes it difficult to use them for vehicle offload, which pretty much means you need a Bay or LPD (with LCU or Mexe) with you in order to move any significant number of vehicles by surface. Although the ramp is nominally rated for Viking, that capability isn't used often, which pretty much limits it to Pinzgauers and TUMs (Landy's to the rest of us). The ramp is a bit on the fragile side as well, as Royal found out when he b8ggered it good and proper about three years ago.
Ocean can obviously deploy troops in surface lift, but that's pretty much it in terms of a differentiator.
As far as build quality goes, Ocean is a bucket of bolts IMO. However, she is the only major warship we have that is designed and built to "commercial standards" - Lloyds Rules and Regulations for Ships to be precise. These should not be confused with Lloyds Rules & Regulations for Naval Ships which is what LPD, QEC and T45 are built and maintained to.