one of the differences that i like the most, between old RQ and new brp parryng method is that skill (and luck) is more important than equipment.
with the old rules having a weapon with lots of ap was very important to get trough a fight specially with high skills, and a warrior with 95% in shield parry and a great parry divine spell, enchanted iron hoplite with armoring or humakti's gifts could easily beat an elder vampire with 200% attack or even old ralzy with his 350% in greatsword.
this is in my opinion not realistic, even with my not extensive combat experience i can easily beat a newby and be easily beaten by a master fighter
equipment can aid but, if you both have two weapons, skill must be the important thing
this is better represented with brp method
since we use brp instead of rq in our games, time taken by combat has become 2/3 shorter with the occasional fight and about the same lenght (maybe a little longer) for great "campaign session ending" battles, this suits well my (and my players) tastes.
the idea of using shields like a passive protection leaves me dubious, while it's real that when using a shield it's difficult to being hit on certain locations, it not impossible and certainly it depens not on the quality of the shield (with some exeptions) but more on the ability of the wielder.