MechaPilot
Explorer
I actually prefer how Hackmaster 5E does it, where you compare your attack roll versus the target's defense roll.
Palladium's games do that as well. I also recall that being one of the variants in the 3e DMG.
Opposed rolls do make a certain degree of sense. However, as you mentioned, this does slow things down a little bit. I don't find the slow-down to be significant enough to be a problem. The real issue regarding "attack roll vs defense roll" for me is the swingy-ness of inserting another die roll; especially a d20. The more RNG you add to both sides of the attack, the less the results seem to reflect the skill of each character.